Surgical instrument with wireless communication between control unit and remote sensor

ABSTRACT

A surgical instrument, such as an endoscopic or laparoscopic instrument. The surgical instrument may comprise an end effector comprising at least one sensor. The surgical instrument may also comprise an electrically conductive shaft having a distal end connected to the end effector wherein the sensor is electrically insulated from the shaft. The surgical instrument may also comprise a handle connected to a proximate end of the shaft. The handle may comprise a control unit electrically coupled to the shaft such that the shaft radiates signals as an antenna from the control unit to the sensor and receives radiated signals from the sensor. Other components electrically coupled to the shaft may also radiate the signals.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application claiming priorityunder 35 U.S.C. § 120 to U.S. patent application Ser. No. 14/559,224,entitled SURGICAL INSTRUMENT WITH WIRELESS COMMUNICATION BETWEEN CONTROLUNIT AND REMOTE SENSOR, filed Dec. 3, 2014, now U.S. Patent ApplicationPublication No. 2015/0090762, which is a continuation applicationclaiming priority under 35 U.S.C. § 120 to U.S. patent application Ser.No. 14/176,671, entitled SURGICAL INSTRUMENT WITH WIRELESS COMMUNICATIONBETWEEN A CONTROL UNIT OF A ROBOTIC SYSTEM AND REMOTE SENSOR, filed Feb.10, 2014, now U.S. Patent Application Publication No. 2014/0171966,which is a continuation application claiming priority under 35 U.S.C. §120 to U.S. patent application Ser. No. 13/118,259, entitled SURGICALINSTRUMENT WITH WIRELESS COMMUNICATION BETWEEN A CONTROL UNIT OF AROBOTIC SYSTEM AND REMOTE SENSOR, filed May 27, 2011, which issued onApr. 1, 2014 as U.S. Pat. No. 8,684,253, which is a continuation-in-partapplication claiming priority under 35 U.S.C. § 120 to U.S. patentapplication Ser. No. 11/651,807, entitled SURGICAL INSTRUMENT WITHWIRELESS COMMUNICATION BETWEEN CONTROL UNIT AND REMOTE SENSOR, filedJan. 10, 2007, which issued on Jun. 11, 2013 as U.S. Pat. No. 8,459,520,the entire disclosures of which are hereby incorporated by referenceherein.

The above listed application are related to the following U.S. PatentApplications, filed Jan. 10, 2007, which are also incorporated herein byreference in their respective entireties:

(1) U.S. patent application Ser. No. 11/651,715, entitled SURGICALINSTRUMENT WITH WIRELESS COMMUNICATION BETWEEN CONTROL UNIT AND SENSORTRANSPONDERS, now U.S. Pat. No. 8,652,120;

(2) U.S. patent application Ser. No. 11/651,806, entitled SURGICALINSTRUMENT WITH ELEMENTS TO COMMUNICATE BETWEEN CONTROL UNIT AND ENDEFFECTOR, now U.S. Pat. No. 7,954,682;

(3) U.S. patent application Ser. No. 11/651,768, entitled PREVENTION OFCARTRIDGE REUSE IN A SURGICAL INSTRUMENT, now U.S. Pat. No. 7,721,931;

(4) U.S. patent application Ser. No. 11/651,771, entitledPOST-STERILIZATION PROGRAMMING OF SURGICAL INSTRUMENTS, now U.S. Pat.No. 7,738,971;

(5) U.S. patent application Ser. No. 11/651,788, entitled INTERLOCK ANDSURGICAL INSTRUMENT INCLUDING SAME, now U.S. Pat. No. 7,721,936; and

(6) U.S. patent application Ser. No. 11/651,785, entitled SURGICALINSTRUMENT WITH ENHANCED BATTERY PERFORMANCE, now U.S. Pat. No.7,900,805.

BACKGROUND

Known surgical staplers include an end effector that simultaneouslymakes a longitudinal incision in tissue and applies lines of staples onopposing sides of the incision. The end effector includes a pair ofcooperating jaw members that, if the instrument is intended forendoscopic or laparoscopic applications, are capable of passing througha cannula passageway. One of the jaw members receives a staple cartridgehaving at least two laterally spaced rows of staples. The other jawmember defines an anvil having staple-forming pockets aligned with therows of staples in the cartridge. The instrument includes a plurality ofreciprocating wedges which, when driven distally, pass through openingsin the staple cartridge and engage drivers supporting the staples toeffect the firing of the staples toward the anvil.

FIGURES

Various embodiments of the present invention are described herein by wayof example in conjunction with the following figures wherein:

FIGS. 1 and 2 are perspective views of a surgical instrument accordingto various embodiments of the present invention;

FIGS. 3-5 are exploded views of an end effector and shaft of theinstrument according to various embodiments of the present invention;

FIG. 6 is a side view of the end effector according to variousembodiments of the present invention;

FIG. 7 is an exploded view of the handle of the instrument according tovarious embodiments of the present invention;

FIGS. 8 and 9 are partial perspective views of the handle according tovarious embodiments of the present invention;

FIG. 10 is a side view of the handle according to various embodiments ofthe present invention;

FIGS. 11, 13-14, 16, and 22 are perspective views of a surgicalinstrument according to various embodiments of the present invention;

FIGS. 12 and 19 are block diagrams of a control unit according tovarious embodiments of the present invention;

FIG. 15 is a side view of an end effector including a sensor transponderaccording to various embodiments of the present invention;

FIGS. 17 and 18 show the instrument in a sterile container according tovarious embodiments of the present invention;

FIG. 20 is a block diagram of the remote programming device according tovarious embodiments of the present invention;

FIG. 21 is a diagram of a packaged instrument according to variousembodiments of the present invention;

FIGS. 23 and 24 are perspective views of a surgical instrument accordingto various embodiments of the present invention;

FIGS. 25-27 are exploded views of an end effector and shaft of theinstrument according to various embodiments of the present invention;

FIG. 28 is a side view of the end effector according to variousembodiments of the present invention;

FIG. 29 is an exploded view of the handle of the instrument according tovarious embodiments of the present invention;

FIGS. 30 and 31 are partial perspective views of the handle according tovarious embodiments of the present invention;

FIG. 32 is a side view of the handle according to various embodiments ofthe present invention;

FIG. 33 is a schematic block diagram of one embodiment of a control unitfor a surgical instrument according to various embodiments of thepresent invention;

FIG. 34 is a schematic diagram illustrating the operation of oneembodiment of the control unit in conjunction with first and secondsensor elements for a surgical instrument according to variousembodiments of the present invention;

FIG. 35 illustrates one embodiment of a surgical instrument comprising afirst element located in a free rotating joint portion of a shaft of thesurgical instrument;

FIG. 36 illustrates one embodiment of a surgical instrument comprisingsensor elements disposed at various locations on a shaft of the surgicalinstrument;

FIG. 37 illustrates one embodiment of a surgical instrument where ashaft of the surgical instrument serves as part of an antenna for acontrol unit;

FIGS. 38 and 39 are perspective views of a surgical instrument accordingto various embodiments of the present invention;

FIG. 40A is an exploded view of the end effector according to variousembodiments of the present invention;

FIG. 40B is a perspective view of the cutting instrument of FIG. 40A;

FIGS. 41 and 42 are exploded views of an end effector and shaft of theinstrument according to various embodiments of the present invention;

FIG. 43 is a side view of the end effector according to variousembodiments of the present invention;

FIG. 44 is an exploded view of the handle of the instrument according tovarious embodiments of the present invention;

FIGS. 45 and 46 are partial perspective views of the handle according tovarious embodiments of the present invention;

FIG. 47 is a side view of the handle according to various embodiments ofthe present invention;

FIGS. 48 and 49 illustrate a proportional sensor that may be usedaccording to various embodiments of the present invention;

FIG. 50 is a block diagram of a control unit according to variousembodiments of the present invention;

FIGS. 51-53 and FIG. 63 are perspective views of a surgical instrumentaccording to various embodiments of the present invention;

FIG. 54 is a bottom view of a portion of a staple cartridge according tovarious embodiments;

FIGS. 55 and 57 are circuit diagrams of a transponder according tovarious embodiments;

FIG. 56 is a bottom view of a portion of a staple cartridge according tovarious embodiments;

FIG. 58 is a perspective view of a staple cartridge tray according tovarious embodiments;

FIGS. 59 and 60 are circuit diagrams of a transponder according tovarious embodiments;

FIG. 61 is a flow diagram of a method of preventing reuse of a staplecartridge in surgical instrument according to various embodiments;

FIG. 62 is a block diagram of a circuit for preventing operation of themotor according to various embodiments;

FIGS. 64 and 65 are perspective views of a surgical cutting andfastening instrument according to various embodiments of the presentinvention;

FIG. 66A is an exploded view of the end effector according to variousembodiments of the present invention;

FIG. 66B is a perspective view of the cutting instrument of FIG. 66A;

FIGS. 67 and 68 are exploded views of an end effector and shaft of theinstrument according to various embodiments of the present invention;

FIG. 69 is a side view of the end effector according to variousembodiments of the present invention;

FIG. 70 is an exploded view of the handle of the instrument according tovarious embodiments of the present invention;

FIGS. 71 and 72 are partial perspective views of the handle according tovarious embodiments of the present invention;

FIG. 73 is a side view of the handle according to various embodiments ofthe present invention;

FIGS. 74-75 illustrate a proportional sensor that may be used accordingto various embodiments of the present invention;

FIGS. 76-90 illustrate mechanical blocking mechanisms and the sequentialoperation of each according to various embodiments of the presentinvention;

FIGS. 91-92 illustrate schematic diagrams of circuits used in theinstrument according to various embodiments of the present invention;

FIG. 93 is a flow diagram of a process implemented by themicrocontroller of FIG. 92 according to various embodiments of thepresent invention; and

FIG. 94 is a flow diagram of a process implemented by an interlockaccording to various embodiments of the present invention.

FIGS. 95-98 illustrate a surgical instrument according other variousembodiments of the present invention.

DETAILED DESCRIPTION

Various embodiments of the present invention are directed generally to asurgical instrument having at least one remote sensor transponder andmeans for communicating power and/or data signals to the transponder(s)from a control unit. The present invention may be used with any type ofsurgical instrument comprising at least one sensor transponder, such asendoscopic or laparoscopic surgical instruments, but is particularlyuseful for surgical instruments where some feature of the instrument,such as a free rotating joint, prevents or otherwise inhibits the use ofa wired connection to the sensor(s). Before describing aspects of thesystem, one type of surgical instrument in which embodiments of thepresent invention may be used—an endoscopic stapling and cuttinginstrument (i.e., an endocutter)—is first described by way ofillustration.

FIGS. 1 and 2 depict an endoscopic surgical instrument 10 that comprisesa handle 6, a shaft 8, and an articulating end effector 12 pivotallyconnected to the shaft 8 at an articulation pivot 14. Correct placementand orientation of the end effector 12 may be facilitated by controls onthe hand 6, including (1) a rotation knob 28 for rotating the closuretube (described in more detail below in connection with FIGS. 4-5) at afree rotating joint 29 of the shaft 8 to thereby rotate the end effector12 and (2) an articulation control 16 to effect rotational articulationof the end effector 12 about the articulation pivot 14. In theillustrated embodiment, the end effector 12 is configured to act as anendocutter for clamping, severing and stapling tissue, although in otherembodiments, different types of end effectors may be used, such as endeffectors for other types of surgical instruments, such as graspers,cutters, staplers, clip appliers, access devices, drug/gene therapydevices, ultrasound, RF or laser devices, etc.

The handle 6 of the instrument 10 may include a closure trigger 18 and afiring trigger 20 for actuating the end effector 12. It will beappreciated that instruments having end effectors directed to differentsurgical tasks may have different numbers or types of triggers or othersuitable controls for operating the end effector 12. The end effector 12is shown separated from the handle 6 by the preferably elongate shaft 8.In one embodiment, a clinician or operator of the instrument 10 mayarticulate the end effector 12 relative to the shaft 8 by utilizing thearticulation control 16, as described in more detail in U.S. patentapplication Ser. No. 11/329,020, filed Jan. 10, 2006, entitled SURGICALINSTRUMENT HAVING AN ARTICULATING END EFFECTOR, now U.S. Pat. No.7,670,334, which is incorporated herein by reference.

The end effector 12 includes in this example, among other things, astaple channel 22 and a pivotally translatable clamping member, such asan anvil 24, which are maintained at a spacing that assures effectivestapling and severing of tissue clamped in the end effector 12. Thehandle 6 includes a pistol grip 26 towards which a closure trigger 18 ispivotally drawn by the clinician to cause clamping or closing of theanvil 24 toward the staple channel 22 of the end effector 12 to therebyclamp tissue positioned between the anvil 24 and channel 22. The firingtrigger 20 is farther outboard of the closure trigger 18. Once theclosure trigger 18 is locked in the closure position, the firing trigger20 may rotate slightly toward the pistol grip 26 so that it can bereached by the operator using one hand. Then the operator may pivotallydraw the firing trigger 20 toward the pistol grip 12 to cause thestapling and severing of clamped tissue in the end effector 12. U.S.patent application Ser. No. 11/343,573, filed Jan. 31, 2006, entitledMOTOR-DRIVEN SURGICAL CUTTING AND FASTENING INSTRUMENT WITH LOADINGFORCE FEEDBACK, now U.S. Pat. No. 7,416,101, (the '573 application)which is incorporated herein by reference, describes variousconfigurations for locking and unlocking the closure trigger 18. Inother embodiments, different types of clamping members besides the anvil24 could be used, such as, for example, an opposing jaw, etc.

It will be appreciated that the terms “proximal” and “distal” are usedherein with reference to a clinician gripping the handle 6 of aninstrument 10. Thus, the end effector 12 is distal with respect to themore proximal handle 6. It will be further appreciated that, forconvenience and clarity, spatial terms such as “vertical” and“horizontal” are used herein with respect to the drawings. However,surgical instruments are used in many orientations and positions, andthese terms are not intended to be limiting and absolute.

The closure trigger 18 may be actuated first. Once the clinician issatisfied with the positioning of the end effector 12, the clinician maydraw back the closure trigger 18 to its fully closed, locked positionproximate to the pistol grip 26. The firing trigger 20 may then beactuated. The firing trigger 20 returns to the open position (shown inFIGS. 1 and 2) when the clinician removes pressure. A release button 30on the handle 6, and in this example, on the pistol grip 26 of thehandle, when depressed may release the locked closure trigger 18.

FIG. 3 is an exploded view of the end effector 12 according to variousembodiments. As shown in the illustrated embodiment, the end effector 12may include, in addition to the previously-mentioned channel 22 andanvil 24, a cutting instrument 32, a sled 33, a staple cartridge 34 thatis removably seated in the channel 22, and a helical screw shaft 36. Thecutting instrument 32 may be, for example, a knife. The anvil 24 may bepivotably opened and closed at a pivot point 25 connected to theproximate end of the channel 22. The anvil 24 may also include a tab 27at its proximate end that is inserted into a component of the mechanicalclosure system (described further below) to open and close the anvil 24.When the closure trigger 18 is actuated, that is, drawn in by a user ofthe instrument 10, the anvil 24 may pivot about the pivot point 25 intothe clamped or closed position. If clamping of the end effector 12 issatisfactory, the operator may actuate the firing trigger 20, which, asexplained in more detail below, causes the knife 32 and sled 33 totravel longitudinally along the channel 22, thereby cutting tissueclamped within the end effector 12. The movement of the sled 33 alongthe channel 22 causes the staples of the staple cartridge 34 to bedriven through the severed tissue and against the closed anvil 24, whichturns the staples to fasten the severed tissue. U.S. Pat. No. 6,978,921,entitled SURGICAL STAPLING INSTRUMENT INCORPORATING AN E-BEAM FIRINGMECHANISM, which is incorporated herein by reference, provides moredetails about such two-stroke cutting and fastening instruments. Thesled 33 may be part of the cartridge 34, such that when the knife 32retracts following the cutting operation, the sled 33 does not retract.The channel 22 and the anvil 24 may be made of an electricallyconductive material (such as metal) so that they may serve as part ofthe antenna that communicates with the sensor(s) in the end effector, asdescribed further below. The cartridge 34 could be made of anonconductive material (such as plastic) and the sensor may be connectedto or disposed in the cartridge 34, as described further below.

It should be noted that although the embodiments of the instrument 10described herein employ an end effector 12 that staples the severedtissue, in other embodiments different techniques for fastening orsealing the severed tissue may be used. For example, end effectors thatuse RF energy or adhesives to fasten the severed tissue may also beused. U.S. Pat. No. 5,709,680, entitled ELECTROSURGICAL HEMOSTATICDEVICE, and U.S. Pat. No. 5,688,270, entitled ELECTROSURGICAL HEMOSTATICDEVICE WITH RECESSED AND/OR OFFSET ELECTRODES, which are incorporatedherein by reference, disclose cutting instruments that use RF energy tofasten the severed tissue. U.S. patent application Ser. No. 11/267,811,now U.S. Pat. No. 7,673,783, and U.S. patent application Ser. No.11/267,383, now U.S. Pat. No. 7,607,557, which are also incorporatedherein by reference, disclose cutting instruments that use adhesives tofasten the severed tissue. Accordingly, although the description hereinrefers to cutting/stapling operations and the like, it should berecognized that this is an exemplary embodiment and is not meant to belimiting. Other tissue-fastening techniques may also be used.

FIGS. 4 and 5 are exploded views and FIG. 6 is a side view of the endeffector 12 and shaft 8 according to various embodiments. As shown inthe illustrated embodiment, the shaft 8 may include a proximate closuretube 40 and a distal closure tube 42 pivotably linked by a pivot links44. The distal closure tube 42 includes an opening 45 into which the tab27 on the anvil 24 is inserted in order to open and close the anvil 24.Disposed inside the closure tubes 40, 42 may be a proximate spine tube46. Disposed inside the proximate spine tube 46 may be a main rotational(or proximate) drive shaft 48 that communicates with a secondary (ordistal) drive shaft 50 via a bevel gear assembly 52. The secondary driveshaft 50 is connected to a drive gear 54 that engages a proximate drivegear 56 of the helical screw shaft 36. The vertical bevel gear 52 b maysit and pivot in an opening 57 in the distal end of the proximate spinetube 46. A distal spine tube 58 may be used to enclose the secondarydrive shaft 50 and the drive gears 54, 56. Collectively, the main driveshaft 48, the secondary drive shaft 50, and the articulation assembly(e.g., the bevel gear assembly 52 a-c), are sometimes referred to hereinas the “main drive shaft assembly.” The closure tubes 40, 42 may be madeof electrically conductive material (such as metal) so that they mayserve as part of the antenna, as described further below. Components ofthe main drive shaft assembly (e.g., the drive shafts 48, 50) may bemade of a nonconductive material (such as plastic).

A bearing 38, positioned at a distal end of the staple channel 22,receives the helical drive screw 36, allowing the helical drive screw 36to freely rotate with respect to the channel 22. The helical screw shaft36 may interface a threaded opening (not shown) of the knife 32 suchthat rotation of the shaft 36 causes the knife 32 to translate distallyor proximately (depending on the direction of the rotation) through thestaple channel 22. Accordingly, when the main drive shaft 48 is causedto rotate by actuation of the firing trigger 20 (as explained in moredetail below), the bevel gear assembly 52 a-c causes the secondary driveshaft 50 to rotate, which in turn, because of the engagement of thedrive gears 54, 56, causes the helical screw shaft 36 to rotate, whichcauses the knife 32 to travel longitudinally along the channel 22 to cutany tissue clamped within the end effector. The sled 33 may be made of,for example, plastic, and may have a sloped distal surface. As the sled33 traverses the channel 22, the sloped forward surface may push up ordrive the staples in the staple cartridge 34 through the clamped tissueand against the anvil 24. The anvil 24 turns the staples, therebystapling the severed tissue. When the knife 32 is retracted, the knife32 and sled 33 may become disengaged, thereby leaving the sled 33 at thedistal end of the channel 22.

According to various embodiments, as shown FIGS. 7-10, the surgicalinstrument may include a battery 64 in the handle 6. The illustratedembodiment provides user-feedback regarding the deployment and loadingforce of the cutting instrument in the end effector 12. In addition, theembodiment may use power provided by the user in retracting the firingtrigger 18 to power the instrument 10 (a so-called “power assist” mode).As shown in the illustrated embodiment, the handle 6 includes exteriorlower side pieces 59, 60 and exterior upper side pieces 61, 62 that fittogether to form, in general, the exterior of the handle 6. The handlepieces 59-62 may be made of an electrically nonconductive material, suchas plastic. A battery 64 may be provided in the pistol grip portion 26of the handle 6. The battery 64 powers a motor 65 disposed in an upperportion of the pistol grip portion 26 of the handle 6. The battery 64may be constructed according to any suitable construction or chemistryincluding, for example, a Li-ion chemistry such as LiCoO₂ or LiNiO₂, aNickel Metal Hydride chemistry, etc. According to various embodiments,the motor 65 may be a DC brushed driving motor having a maximum rotationof, approximately, 5000 RPM to 100,000 RPM. The motor 64 may drive a 90°bevel gear assembly 66 comprising a first bevel gear 68 and a secondbevel gear 70. The bevel gear assembly 66 may drive a planetary gearassembly 72. The planetary gear assembly 72 may include a pinion gear 74connected to a drive shaft 76. The pinion gear 74 may drive a matingring gear 78 that drives a helical gear drum 80 via a drive shaft 82. Aring 84 may be threaded on the helical gear drum 80. Thus, when themotor 65 rotates, the ring 84 is caused to travel along the helical geardrum 80 by means of the interposed bevel gear assembly 66, planetarygear assembly 72 and ring gear 78.

The handle 6 may also include a run motor sensor 110 in communicationwith the firing trigger 20 to detect when the firing trigger 20 has beendrawn in (or “closed”) toward the pistol grip portion 26 of the handle 6by the operator to thereby actuate the cutting/stapling operation by theend effector 12. The sensor 110 may be a proportional sensor such as,for example, a rheostat or variable resistor. When the firing trigger 20is drawn in, the sensor 110 detects the movement, and sends anelectrical signal indicative of the voltage (or power) to be supplied tothe motor 65. When the sensor 110 is a variable resistor or the like,the rotation of the motor 65 may be generally proportional to the amountof movement of the firing trigger 20. That is, if the operator onlydraws or closes the firing trigger 20 in a little bit, the rotation ofthe motor 65 is relatively low. When the firing trigger 20 is fullydrawn in (or in the fully closed position), the rotation of the motor 65is at its maximum. In other words, the harder the user pulls on thefiring trigger 20, the more voltage is applied to the motor 65, causinggreater rates of rotation. In another embodiment, for example, thecontrol unit (described further below) may output a PWM control signalto the motor 65 based on the input from the sensor 110 in order tocontrol the motor 65.

The handle 6 may include a middle handle piece 104 adjacent to the upperportion of the firing trigger 20. The handle 6 also may comprise a biasspring 112 connected between posts on the middle handle piece 104 andthe firing trigger 20. The bias spring 112 may bias the firing trigger20 to its fully open position. In that way, when the operator releasesthe firing trigger 20, the bias spring 112 will pull the firing trigger20 to its open position, thereby removing actuation of the sensor 110,thereby stopping rotation of the motor 65. Moreover, by virtue of thebias spring 112, any time a user closes the firing trigger 20, the userwill experience resistance to the closing operation, thereby providingthe user with feedback as to the amount of rotation exerted by the motor65. Further, the operator could stop retracting the firing trigger 20 tothereby remove force from the sensor 100, to thereby stop the motor 65.As such, the user may stop the deployment of the end effector 12,thereby providing a measure of control of the cutting/fasteningoperation to the operator.

The distal end of the helical gear drum 80 includes a distal drive shaft120 that drives a ring gear 122, which mates with a pinion gear 124. Thepinion gear 124 is connected to the main drive shaft 48 of the maindrive shaft assembly. In that way, rotation of the motor 65 causes themain drive shaft assembly to rotate, which causes actuation of the endeffector 12, as described above.

The ring 84 threaded on the helical gear drum 80 may include a post 86that is disposed within a slot 88 of a slotted arm 90. The slotted arm90 has an opening 92 at its opposite end 94 that receives a pivot pin 96that is connected between the handle exterior side pieces 59, 60. Thepivot pin 96 is also disposed through an opening 100 in the firingtrigger 20 and an opening 102 in the middle handle piece 104.

In addition, the handle 6 may include a reverse motor (or end-of-strokesensor) 130 and a stop motor (or beginning-of-stroke) sensor 142. Invarious embodiments, the reverse motor sensor 130 may be a limit switchlocated at the distal end of the helical gear drum 80 such that the ring84 threaded on the helical gear drum 80 contacts and trips the reversemotor sensor 130 when the ring 84 reaches the distal end of the helicalgear drum 80. The reverse motor sensor 130, when activated, sends asignal to the control unit which sends a signal to the motor 65 toreverse its rotation direction, thereby withdrawing the knife 32 of theend effector 12 following the cutting operation.

The stop motor sensor 142 may be, for example, a normally-closed limitswitch. In various embodiments, it may be located at the proximate endof the helical gear drum 80 so that the ring 84 trips the switch 142when the ring 84 reaches the proximate end of the helical gear drum 80.

In operation, when an operator of the instrument 10 pulls back thefiring trigger 20, the sensor 110 detects the deployment of the firingtrigger 20 and sends a signal to the control unit which sends a signalto the motor 65 to cause forward rotation of the motor 65 at, forexample, a rate proportional to how hard the operator pulls back thefiring trigger 20. The forward rotation of the motor 65 in turn causesthe ring gear 78 at the distal end of the planetary gear assembly 72 torotate, thereby causing the helical gear drum 80 to rotate, causing thering 84 threaded on the helical gear drum 80 to travel distally alongthe helical gear drum 80. The rotation of the helical gear drum 80 alsodrives the main drive shaft assembly as described above, which in turncauses deployment of the knife 32 in the end effector 12. That is, theknife 32 and sled 33 are caused to traverse the channel 22longitudinally, thereby cutting tissue clamped in the end effector 12.Also, the stapling operation of the end effector 12 is caused to happenin embodiments where a stapling-type end effector is used.

By the time the cutting/stapling operation of the end effector 12 iscomplete, the ring 84 on the helical gear drum 80 will have reached thedistal end of the helical gear drum 80, thereby causing the reversemotor sensor 130 to be tripped, which sends a signal to the control unitwhich sends a signal to the motor 65 to cause the motor 65 to reverseits rotation. This in turn causes the knife 32 to retract, and alsocauses the ring 84 on the helical gear drum 80 to move back to theproximate end of the helical gear drum 80.

The middle handle piece 104 includes a backside shoulder 106 thatengages the slotted arm 90 as best shown in FIGS. 8 and 9. The middlehandle piece 104 also has a forward motion stop 107 that engages thefiring trigger 20. The movement of the slotted arm 90 is controlled, asexplained above, by rotation of the motor 65. When the slotted arm 90rotates CCW as the ring 84 travels from the proximate end of the helicalgear drum 80 to the distal end, the middle handle piece 104 will be freeto rotate CCW. Thus, as the user draws in the firing trigger 20, thefiring trigger 20 will engage the forward motion stop 107 of the middlehandle piece 104, causing the middle handle piece 104 to rotate CCW. Dueto the backside shoulder 106 engaging the slotted arm 90, however, themiddle handle piece 104 will only be able to rotate CCW as far as theslotted arm 90 permits. In that way, if the motor 65 should stoprotating for some reason, the slotted arm 90 will stop rotating, and theuser will not be able to further draw in the firing trigger 20 becausethe middle handle piece 104 will not be free to rotate CCW due to theslotted arm 90.

Components of an exemplary closure system for closing (or clamping) theanvil 24 of the end effector 12 by retracting the closure trigger 18 arealso shown in FIGS. 7-10. In the illustrated embodiment, the closuresystem includes a yoke 250 connected to the closure trigger 18 by a pin251 that is inserted through aligned openings in both the closuretrigger 18 and the yoke 250. A pivot pin 252, about which the closuretrigger 18 pivots, is inserted through another opening in the closuretrigger 18 which is offset from where the pin 251 is inserted throughthe closure trigger 18. Thus, retraction of the closure trigger 18causes the upper part of the closure trigger 18, to which the yoke 250is attached via the pin 251, to rotate CCW. The distal end of the yoke250 is connected, via a pin 254, to a first closure bracket 256. Thefirst closure bracket 256 connects to a second closure bracket 258.Collectively, the closure brackets 256, 258 define an opening in whichthe proximate end of the proximate closure tube 40 (see FIG. 4) isseated and held such that longitudinal movement of the closure brackets256, 258 causes longitudinal motion by the proximate closure tube 40.The instrument 10 also includes a closure rod 260 disposed inside theproximate closure tube 40. The closure rod 260 may include a window 261into which a post 263 on one of the handle exterior pieces, such asexterior lower side piece 59 in the illustrated embodiment, is disposedto fixedly connect the closure rod 260 to the handle 6. In that way, theproximate closure tube 40 is capable of moving longitudinally relativeto the closure rod 260. The closure rod 260 may also include a distalcollar 267 that fits into a cavity 269 in proximate spine tube 46 and isretained therein by a cap 271 (see FIG. 4).

In operation, when the yoke 250 rotates due to retraction of the closuretrigger 18, the closure brackets 256, 258 cause the proximate closuretube 40 to move distally (i.e., away from the handle end of theinstrument 10), which causes the distal closure tube 42 to movedistally, which causes the anvil 24 to rotate about the pivot point 25into the clamped or closed position. When the closure trigger 18 isunlocked from the locked position, the proximate closure tube 40 iscaused to slide proximately, which causes the distal closure tube 42 toslide proximately, which, by virtue of the tab 27 being inserted in thewindow 45 of the distal closure tube 42, causes the anvil 24 to pivotabout the pivot point 25 into the open or unclamped position. In thatway, by retracting and locking the closure trigger 18, an operator mayclamp tissue between the anvil 24 and channel 22, and may unclamp thetissue following the cutting/stapling operation by unlocking the closuretrigger 18 from the locked position.

The control unit (described further below) may receive the outputs fromend-of-stroke and beginning-of-stroke sensors 130, 142 and the run-motorsensor 110, and may control the motor 65 based on the inputs. Forexample, when an operator initially pulls the firing trigger 20 afterlocking the closure trigger 18, the run-motor sensor 110 is actuated. Ifthe staple cartridge 34 is present in the end effector 12, a cartridgelockout sensor (not shown) may be closed, in which case the control unitmay output a control signal to the motor 65 to cause the motor 65 torotate in the forward direction. When the end effector 12 reaches theend of its stroke, the reverse motor sensor 130 will be activated. Thecontrol unit may receive this output from the reverse motor sensor 130and cause the motor 65 to reverse its rotational direction. When theknife 32 is fully retracted, the stop motor sensor switch 142 isactivated, causing the control unit to stop the motor 65.

In other embodiments, rather than a proportional-type sensor 110, anon-off type sensor could be used. In such embodiments, the rate ofrotation of the motor 65 would not be proportional to the force appliedby the operator. Rather, the motor 65 would generally rotate at aconstant rate. But the operator would still experience force feedbackbecause the firing trigger 20 is geared into the gear drive train.

The instrument 10 may include a number of sensor transponders in the endeffector 12 for sensing various conditions related to the end effector12, such as sensor transponders for determining the status of the staplecartridge 34 (or other type of cartridge depending on the type ofsurgical instrument), the progress of the stapler during closure andfiring, etc. The sensor transponders may be passively powered byinductive signals, as described further below, although in otherembodiments the transponders could be powered by a remote power source,such as a battery in the end effector 12, for example. The sensortransponder(s) could include magnetoresistive, optical,electromechanical, RFID, MEMS, motion or pressure sensors, for example.These sensor transponders may be in communication with a control unit300, which may be housed in the handle 6 of the instrument 10, forexample, as shown in FIG. 11.

As shown in FIG. 12, according to various embodiments the control unit300 may comprise a processor 306 and one or more memory units 308. Byexecuting instruction code stored in the memory 308, the processor 306may control various components of the instrument 10, such as the motor65 or a user display (not shown), based on inputs received from thevarious end effector sensor transponders and other sensor(s) (such asthe run-motor sensor 110, the end-of-stroke sensor 130, and thebeginning-of-stroke sensor 142, for example). The control unit 300 maybe powered by the battery 64 during surgical use of instrument 10. Thecontrol unit 300 may comprise an inductive element 302 (e.g., a coil orantenna) to pick up wireless signals from the sensor transponders, asdescribed in more detail below. Input signals received by the inductiveelement 302 acting as a receiving antenna may be demodulated by ademodulator 310 and decoded by a decoder 312. The input signals maycomprise data from the sensor transponders in the end effector 12, whichthe processor 306 may use to control various aspects of the instrument10.

To transmit signals to the sensor transponders, the control unit 300 maycomprise an encoder 316 for encoding the signals and a modulator 318 formodulating the signals according to the modulation scheme. The inductiveelement 302 may act as the transmitting antenna. The control unit 300may communicate with the sensor transponders using any suitable wirelesscommunication protocol and any suitable frequency (e.g., an ISM band).Also, the control unit 300 may transmit signals at a different frequencyrange than the frequency range of the received signals from the sensortransponders. Also, although only one antenna (inductive element 302) isshown in FIG. 12, in other embodiments the control unit 300 may haveseparate receiving and transmitting antennas.

According to various embodiments, the control unit 300 may comprise amicrocontroller, a microprocessor, a field programmable gate array(FPGA), one or more other types of integrated circuits (e.g., RFreceivers and PWM controllers), and/or discrete passive components. Thecontrol units may also be embodied as system-on-chip (SoC) or asystem-in-package (SIP), for example.

As shown in FIG. 11, the control unit 300 may be housed in the handle 6of the instrument 10 and one or more of the sensor transponders 368 forthe instrument 10 may be located in the end effector 12. To deliverpower and/or transmit data to or from the sensor transponders 368 in theend effector 12, the inductive element 302 of the control unit 300 maybe inductively coupled to a secondary inductive element (e.g., a coil)320 positioned in the shaft 8 distally from the rotation joint 29. Thesecondary inductive element 320 is preferably electrically insulatedfrom the conductive shaft 8.

The secondary inductive element 320 may be connected by an electricallyconductive, insulated wire 322 to a distal inductive element (e.g., acoil) 324 located near the end effector 12, and preferably distallyrelative to the articulation pivot 14. The wire 322 may be made of anelectrically conductive polymer and/or metal (e.g., copper) and may besufficiently flexible so that it could pass though the articulationpivot 14 and not be damaged by articulation. The distal inductiveelement 324 may be inductively coupled to the sensor transponder 368 in,for example, the cartridge 34 of the end effector 12. The transponder368, as described in more detail below, may include an antenna (or coil)for inductive coupling to the distal coil 324, a sensor and integratedcontrol electronics for receiving and transmitting wirelesscommunication signals.

The transponder 368 may use a portion of the power of the inductivesignal received from the distal inductive element 326 to passively powerthe transponder 368. Once sufficiently powered by the inductive signals,the transponder 368 may receive and transmit data to the control unit300 in the handle 6 via (i) the inductive coupling between thetransponder 368 and the distal inductive element 324, (ii) the wire 322,and (iii) the inductive coupling between the secondary inductive element320 and the control unit 300. That way, the control unit 300 maycommunicate with the transponder 368 in the end effector 12 without adirect wired connection through complex mechanical joints like therotating joint 29 and/or without a direct wired connection from theshaft 8 to the end effector 12, places where it may be difficult tomaintain such a wired connection. In addition, because the distancesbetween the inductive elements (e.g., the spacing between (i) thetransponder 368 and the distal inductive element 324, and (ii) thesecondary inductive element 320 and the control unit 300) and fixed andknown, the couplings could be optimized for inductive transfer ofenergy. Also, the distances could be relatively short so that relativelylow power signals could be used to thereby minimize interference withother systems in the use environment of the instrument 10.

In the embodiment of FIG. 12, the inductive element 302 of the controlunit 300 is located relatively near to the control unit 300. Accordingto other embodiments, as shown in FIG. 13, the inductive element 302 ofthe control unit 300 may be positioned closer to the rotating joint 29to that it is closer to the secondary inductive element 320, therebyreducing the distance of the inductive coupling in such an embodiment.Alternatively, the control unit 300 (and hence the inductive element302) could be positioned closer to the secondary inductive element 320to reduce the spacing.

In other embodiments, more or fewer than two inductive couplings may beused. For example, in some embodiments, the surgical instrument 10 mayuse a single inductive coupling between the control unit 300 in thehandle 6 and the transponder 368 in the end effector 12, therebyeliminating the inductive elements 320, 324 and the wire 322. Of course,in such an embodiment, a stronger signal may be required due to thegreater distance between the control unit 300 in the handle 6 and thetransponder 368 in the end effector 12. Also, more than two inductivecouplings could be used. For example, if the surgical instrument 10 hadnumerous complex mechanical joints where it would be difficult tomaintain a direct wired connection, inductive couplings could be used tospan each such joint. For example, inductive couplers could be used onboth sides of the rotary joint 29 and both sides of the articulationpivot 14, with the inductive element 321 on the distal side of therotary joint 29 connected by a wire 322 to the inductive element 324 ofthe proximate side of the articulation pivot, and a wire 323 connectingthe inductive elements 325, 326 on the distal side of the articulationpivot 14 as shown in FIG. 14. In this embodiment, the inductive element326 may communicate with the sensor transponder 368.

In addition, the transponder 368 may include a number of differentsensors. For example, it may include an array of sensors. Further, theend effector 12 could include a number of sensor transponders 368 incommunication with the distal inductive element 324 (and hence thecontrol unit 300). Also, the inductive elements 320, 324 may or may notinclude ferrite cores. As mentioned before, they are also preferablyinsulated from the electrically conductive outer shaft (or frame) of theinstrument 10 (e.g., the closure tubes 40, 42), and the wire 322 is alsopreferably insulated from the outer shaft 8.

FIG. 15 is a diagram of an end effector 12 including a transponder 368held or embedded in the cartridge 34 at the distal end of the channel22. The transponder 368 may be connected to the cartridge 34 by asuitable bonding material, such as epoxy. In this embodiment, thetransponder 368 includes a magnetoresistive sensor. The anvil 24 alsoincludes a permanent magnet 369 at its distal end and generally facingthe transponder 368. The end effector 12 also includes a permanentmagnet 370 connected to the sled 33 in this example embodiment. Thisallows the transponder 368 to detect both opening/closing of the endeffector 12 (due to the permanent magnet 369 moving further or closer tothe transponder as the anvil 24 opens and closes) and completion of thestapling/cutting operation (due to the permanent magnet 370 movingtoward the transponder 368 as the sled 33 traverses the channel 22 aspart of the cutting operation).

FIG. 15 also shows the staples 380 and the staple drivers 382 of thestaple cartridge 34. As explained previously, according to variousembodiments, when the sled 33 traverses the channel 22, the sled 33drives the staple drivers 382 which drive the staples 380 into thesevered tissue held in the end effector 12, the staples 380 being formedagainst the anvil 24. As noted above, such a surgical cutting andfastening instrument is but one type of surgical instrument in which thepresent invention may be advantageously employed. Various embodiments ofthe present invention may be used in any type of surgical instrumenthaving one or more sensor transponders.

In the embodiments described above, the battery 64 powers (at leastpartially) the firing operation of the instrument 10. As such, theinstrument may be a so-called “power-assist” device. More details andadditional embodiments of power-assist devices are described in the '573application, which is incorporated herein. It should be recognized,however, that the instrument 10 need not be a power-assist device andthat this is merely an example of a type of device that may utilizeaspects of the present invention. For example, the instrument 10 mayinclude a user display (such as a LCD or LED display) that is powered bythe battery 64 and controlled by the control unit 300. Data from thesensor transponders 368 in the end effector 12 may be displayed on sucha display.

In another embodiment, the shaft 8 of the instrument 10, including forexample, the proximate closure tube 40 and the distal closure tube 42,may collectively serve as part of an antenna for the control unit 300 byradiating signals to the sensor transponder 368 and receiving radiatedsignals from the sensor transponder 368. That way, signals to and fromthe remote sensor in the end effector 12 may be transmitted via theshaft 8 of the instrument 10.

The proximate closure tube 40 may be grounded at its proximate end bythe exterior lower and upper side pieces 59-62, which may be made of anonelectrically conductive material, such as plastic. The drive shaftassembly components (including the main drive shaft 48 and secondarydrive shaft 50) inside the proximate and distal closure tubes 40, 42 mayalso be made of a nonelectrically conductive material, such as plastic.Further, components of end effector 12 (such as the anvil 24 and thechannel 22) may be electrically coupled to (or in direct or indirectelectrical contact with) the distal closure tube 42 such that they mayalso serve as part of the antenna. Further, the sensor transponder 368could be positioned such that it is electrically insulated from thecomponents of the shaft 8 and end effector 12 serving as the antenna.For example, the sensor transponder 368 may be positioned in thecartridge 34, which may be made of a nonelectrically conductivematerial, such as plastic. Because the distal end of the shaft 8 (suchas the distal end of the distal closure tube 42) and the portions of theend effector 12 serving as the antenna may be relatively close indistance to the sensor 368, the power for the transmitted signals may beheld at low levels, thereby minimizing or reducing interference withother systems in the use environment of the instrument 10.

In such an embodiment, as shown in FIG. 16, the control unit 300 may beelectrically coupled to the shaft 8 of the instrument 10, such as to theproximate closure tube 40, by a conductive link 400 (e.g., a wire).Portions of the outer shaft 8, such as the closure tubes 40, 42, maytherefore act as part of an antenna for the control unit 300 byradiating signals to the sensor 368 and receiving radiated signals fromthe sensor 368. Input signals received by the control unit 300 may bedemodulated by the demodulator 310 and decoded by the decoder 312 (seeFIG. 12). The input signals may comprise data from the sensors 368 inthe end effector 12, which the processor 306 may use to control variousaspects of the instrument 10, such as the motor 65 or a user display.

To transmit data signals to or from the sensors 368 in the end effector12, the link 400 may connect the control unit 300 to components of theshaft 8 of the instrument 10, such as the proximate closure tube 40,which may be electrically connected to the distal closure tube 42. Thedistal closure tube 42 is preferably electrically insulated from theremote sensor 368, which may be positioned in the plastic cartridge 34(see FIG. 3). As mentioned before, components of the end effector 12,such as the channel 22 and the anvil 24 (see FIG. 3), may be conductiveand in electrical contact with the distal closure tube 42 such thatthey, too, may serve as part of the antenna.

With the shaft 8 acting as the antenna for the control unit 300, thecontrol unit 300 can communicate with the sensor 368 in the end effector12 without a direct wired connection. In addition, because the distancesbetween shaft 8 and the remote sensor 368 is fixed and known, the powerlevels could be optimized for low levels to thereby minimizeinterference with other systems in the use environment of the instrument10. The sensor 368 may include communication circuitry for radiatingsignals to the control unit 300 and for receiving signals from thecontrol unit 300, as described above. The communication circuitry may beintegrated with the sensor 368.

In another embodiment, the components of the shaft 8 and/or the endeffector 12 may serve as an antenna for the remote sensor 368. In suchan embodiment, the remote sensor 368 is electrically connected to theshaft (such as to distal closure tube 42, which may be electricallyconnected to the proximate closure tube 40) and the control unit 300 isinsulated from the shaft 8. For example, the sensor 368 could beconnected to a conductive component of the end effector 12 (such as thechannel 22), which in turn may be connected to conductive components ofthe shaft (e.g., the closure tubes 40, 42). Alternatively, the endeffector 12 may include a wire (not shown) that connects the remotesensor 368 the distal closure tube 42.

Typically, surgical instruments, such as the instrument 10, are cleanedand sterilized prior to use. In one sterilization technique, theinstrument 10 is placed in a closed and sealed container 280, such as aplastic or TYVEK container or bag, as shown in FIGS. 17 and 18. Thecontainer and the instrument are then placed in a field of radiationthat can penetrate the container, such as gamma radiation, x-rays, orhigh-energy electrons. The radiation kills bacteria on the instrument 10and in the container 280. The sterilized instrument 10 can then bestored in the sterile container 280. The sealed, sterile container 280keeps the instrument 10 sterile until it is opened in a medical facilityor some other use environment. Instead of radiation, other means ofsterilizing the instrument 10 may be used, such as ethylene oxide orsteam.

When radiation, such as gamma radiation, is used to sterilize theinstrument 10, components of the control unit 300, particularly thememory 308 and the processor 306, may be damaged and become unstable.Thus, according to various embodiments of the present invention, thecontrol unit 300 may be programmed after packaging and sterilization ofthe instrument 10.

As shown in FIG. 17, a remote programming device 320, which may be ahandheld device, may be brought into wireless communication with thecontrol unit 300. The remote programming device 320 may emit wirelesssignals that are received by the control unit 300 to program the controlunit 300 and to power the control unit 300 during the programmingoperation. That way, the battery 64 does not need to power the controlunit 300 during the programming operation. According to variousembodiments, the programming code downloaded to the control unit 300could be of relatively small size, such as 1 MB or less, so that acommunications protocol with a relatively low data transmission ratecould be used if desired. Also, the remote programming unit 320 could bebrought into close physical proximity with the surgical instrument 10 sothat a low power signal could be used.

Referring back to FIG. 19, the control unit 300 may comprise aninductive coil 402 to pick up wireless signals from a remote programmingdevice 320. A portion of the received signal may be used by a powercircuit 404 to power the control unit 300 when it is not being poweredby the battery 64.

Input signals received by the coil 402 acting as a receiving antenna maybe demodulated by a demodulator 410 and decoded by a decoder 412. Theinput signals may comprise programming instructions (e.g., code), whichmay be stored in a non-volatile memory portion of the memory 308. Theprocessor 306 may execute the code when the instrument 10 is inoperation. For example, the code may cause the processor 306 to outputcontrol signals to various sub-systems of the instrument 10, such as themotor 65, based on data received from the sensors 368.

The control unit 300 may also comprise a non-volatile memory unit 414that comprises boot sequence code for execution by the processor 306.When the control unit 300 receives enough power from the signals fromthe remote control unit 320 during the post-sterilization programmingoperation, the processor 306 may first execute the boot sequence code(“boot loader”) 414, which may load the processor 306 with an operatingsystem.

The control unit 300 may also send signals back to the remoteprogramming unit 320, such as acknowledgement and handshake signals, forexample. The control unit 300 may comprise an encoder 416 for encodingthe signals to then be sent to the programming device 320 and amodulator 418 for modulating the signals according to the modulationscheme. The coil 402 may act as the transmitting antenna. The controlunit 300 and the remote programming device 320 may communicate using anysuitable wireless communication protocol (e.g., Bluetooth) and anysuitable frequency (e.g., an ISM band). Also, the control unit 300 maytransmit signals at a different frequency range than the frequency rangeof the received signals from the remote programming unit 320.

FIG. 20 is a simplified diagram of the remote programming device 320according to various embodiments of the present invention. As shown inFIG. 20, the remote programming unit 320 may comprise a main controlboard 230 and a boosted antenna board 232. The main control board 230may comprise a controller 234, a power module 236, and a memory 238. Thememory 238 may stored the operating instructions for the controller 234as well as the programming instructions to be transmitted to the controlunit 300 of the surgical instrument 10. The power module 236 may providea stable DC voltage for the components of the remote programming device320 from an internal battery (not shown) or an external AC or DC powersource (not shown).

The boosted antenna board 232 may comprise a coupler circuit 240 that isin communication with the controller 234 via an I²C bus, for example.The coupler circuit 240 may communicate with the control unit 300 of thesurgical instrument via an antenna 244. The coupler circuit 240 mayhandle the modulating/demodulating and encoding/decoding operations fortransmissions with the control unit. According to other embodiments, theremote programming device 320 could have a discrete modulator,demodulator, encoder and decoder. As shown in FIG. 20, the boost antennaboard 232 may also comprise a transmitting power amp 246, a matchingcircuit 248 for the antenna 244, and a filter/amplifier 249 forreceiving signals.

According to other embodiments, as shown in FIG. 20, the remoteprogramming device could be in communication with a computer device 460,such as a PC or a laptop, via a USB and/or RS232 interface, for example.In such a configuration, a memory of the computing device 460 may storethe programming instructions to be transmitted to the control unit 300.In another embodiment, the computing device 460 could be configured witha wireless transmission system to transmit the programming instructionsto the control unit 300.

In addition, according to other embodiments, rather than using inductivecoupling between the control unit 300 and the remote programming device320, capacitively coupling could be used. In such an embodiment, thecontrol unit 300 could have a plate instead of a coil, as could theremote programming unit 320.

In another embodiment, rather than using a wireless communication linkbetween the control unit 300 and the remote programming device 320, theprogramming device 320 may be physically connected to the control unit300 while the instrument 10 is in its sterile container 280 in such away that the instrument 10 remains sterilized. FIG. 21 is a diagram of apackaged instrument 10 according to such an embodiment. As shown in FIG.22, the handle 6 of the instrument 10 may include an external connectioninterface 470. The container 280 may further comprise a connectioninterface 472 that mates with the external connection interface 470 ofthe instrument 10 when the instrument 10 is packaged in the container280. The programming device 320 may include an external connectioninterface (not shown) that may connect to the connection interface 472at the exterior of the container 280 to thereby provide a wiredconnection between the programming device 320 and the externalconnection interface 470 of the instrument 10.

In one embodiment, the present invention is directed to a surgicalinstrument, such as an endoscopic or laparoscopic instrument. Thesurgical instrument may comprise a shaft having a distal end connectedto an end effector and a handle connected to a proximate end of theshaft. The handle may comprise a control unit (e.g., a microcontroller)that is in communication with a first sensor element. Further, thesurgical instrument may comprise a rotational joint for rotating theshaft. In such a case, the surgical instrument may comprise the firstelement located in the shaft distally from the rotational joint. Thefirst element may be coupled to the control unit either by a wired orwireless electrical connection. A second element may be located in theend effector and may be coupled to the first element by a wirelesselectrical connection. The first and second elements may be connectedand/or coupled by a wired or a wireless electrical connection.

The control unit may communicate with the second sensor element in theend effector without a direct wired electrical connection throughcomplex mechanical joints like a rotating joint or articulating pivotwhere it may be difficult to maintain such a wired electricalconnection. In addition, because the distances between the inductiveelements may be fixed and known, the couplings between the first andsecond sensor elements may be optimized for inductive and/orelectromagnetic transfer of energy. Also, the distances may berelatively short so that relatively low power signals may be used tominimize interference with other systems in the use environment of theinstrument.

In another embodiment of the present invention, the electricallyconductive shaft of the surgical instrument may serve as an antenna forthe control unit to wirelessly communicate signals to and from one ormore sensor elements. For example, one or more sensor elements may belocated on or disposed in a nonconductive component of the end effector,such as a plastic cartridge, thereby insulating the sensor element fromconductive components of the end effector and the shaft. In addition,the control unit in the handle may be electrically coupled to the shaft.In that way, the shaft and/or the end effector may serve as an antennafor the control unit to radiate signals from the control unit to the oneor more sensor elements and/or receive radiated echo response signalsfrom the one or more sensor elements. Such a design is particularlyuseful in surgical instruments having complex mechanical joints (such asrotary joints) and articulating pivots, which make it difficult to use adirect wired electrical connection between the sensor elements and thecontrol unit for communicating electrical signals therebetween.

Various embodiments of the present invention are directed generally to asurgical instrument comprising one or more sensor elements to sense thelocation, type, presence and/or status of various components of interestdisposed on the surgical instrument. In one embodiment, the presentinvention is directed generally to a surgical instrument having one ormore sensor elements to sense the location, type, presence and/or statusof various components of interest disposed in an end effector portion ofthe surgical instrument. These components of interest may comprise, forexample, a sled, a staple cartridge, a cutting instrument or any othercomponent that may be disposed on the surgical instrument and moreparticularly disposed in the end effector portion thereof. Although thepresent invention may be used with any type of surgical instrument suchas endoscopic or laparoscopic surgical instruments, it is particularlyuseful for surgical instruments comprising one or more free rotatingjoints or an articulation pivots that make it difficult to use wiredelectrical connections to the one or more passive and/or active sensorelements.

The one or more sensor elements may be passive or active sensor elementsadapted to communicate with a control unit in any suitable manner. Invarious embodiments, some of the sensor elements may not be suppliedpower over a wired electrical connection and as described herein,neither the passive nor the active sensor elements may comprise aninternal power supply. The sensor elements may operate using the powerprovided by the minute electrical current induced in the sensor elementitself or an antenna coupled to the sensor element by an incoming radiofrequency (RF) interrogation signal transmitted by the control unit.This means that the antenna and/or the sensor element itself may bedesigned to collect power from the incoming interrogation signal andalso to transmit an outbound backscatter signal in response thereto. Thelack of an onboard power supply means that the sensor elements may havea relatively small form factor. In embodiments comprising a passivesensor element RF interrogation signals may be received by the passivesensor element wirelessly over a predetermined channel. The incidentelectromagnetic radiation associated with the RF interrogation signalsis then scattered or reflected back to the interrogating source such asthe control unit. Thus, the passive sensor element signals bybackscattering the carrier of the RF interrogation signal from thecontrol unit. In embodiments comprising an active sensor element, on theother hand, just enough power may be received from the RF interrogationsignals to cause the active sensor element to power up and transmit ananalog or digital signal back to the control unit in response inresponse to the RF interrogation signal. The control unit may bereferred to as a reader, interrogator or the like.

In one embodiment, the status of a component (e.g., sled, staplecartridge, cutting instrument) located in the end effector portion ofthe surgical instrument may be determined through the use of a systemcomprising passive and/or active sensor elements coupled to a controlunit. The passive sensor elements may be formed of or comprise passivehardware elements such as resistive, inductive and/or capacitiveelements or any combination thereof. The active sensor elements may beformed of or comprise active hardware elements. These active hardwareelements may be integrated and/or discrete circuit elements or anycombination thereof. Examples of integrated and/or discrete hardwareelements are described herein below.

In one embodiment, the system may comprise a control unit coupled to aprimary sensor element (primary element) disposed at a distal end of ashaft of the surgical instrument prior to an articulation pivot (asdescribed below) and a secondary sensor element (secondary element)disposed on a component of interest in an end effector portion of thesurgical instrument located subsequent to the articulation pivot (e.g.,on a sled as described below). Rather than transmitting continuous powerto the secondary element over a wired electrical connection, the primaryelement wirelessly interrogates or illuminates the secondary element bytransmitting an electromagnetic pulse signal over a channel at apredetermined frequency, duration and repetition rate. When theinterrogation pulse signal is incident upon, i.e., strikes orilluminates, the secondary element, it generated an echo responsesignal. The echo response signal is a reflection of the electromagneticenergy incident upon the secondary element. After transmitting theinterrogation signal, the primary element listens for the echo responsesignal reflected from the secondary element and couples the echoresponse signal to the control unit in a suitable form for subsequentprocessing. The echo response signal may be of the same frequency as theinterrogation pulse or some harmonic frequency thereof. The amount ofreflected energy in the echo response signal depends upon the material,shape and size of the secondary element. The amount of reflected energyin the echo response signal also depends upon the distance between theprimary element and the secondary element. Therefore, the material,shape and size of the secondary element as well as the relative distancebetween the primary and secondary elements may be selected to generate aunique echo response signal that is indicative of a desired measurementassociated with the component of interest coupled to the secondaryelement. For example, unique echo response signals may indicate thelocation, type, presence and/or status of various components andsub-components disposed in the surgical instrument. Especially, thevarious components and sub-components disposed in the end effectorportion of the surgical instrument subsequent to a freely rotating jointor articulation pivot that may make it difficult or impractical toprovide a wired electrical connection between the primary and thesecondary elements. The echo response signals also may be used todetermine the distance between the primary and secondary elements. Inthis manner, the secondary element may be made integral with or may beattached to a component of interest and the echo response signal mayprovide information associated with the component of interest. Thisarrangement may eliminate the need to transmit or provide power to thesecondary element over a wired connection and may be a cost effectivesolution to providing various additional passive and/or active sensorelements in the surgical instrument. Before describing aspects of thesystem, one type of surgical instrument in which embodiments of thepresent invention may be used—an endoscopic stapling and cuttinginstrument (i.e., an endocutter)—is first described by way ofillustration.

FIGS. 23 and 24 depict an endoscopic surgical instrument 2010 thatcomprises a handle 2006, a shaft 2008, and an articulating end effector2012 pivotally connected to the shaft 2008 at an articulation pivot2014. Correct placement and orientation of the end effector 2012 may befacilitated by controls on the hand 2006, including (1) a rotation knob2028 for rotating the closure tube (described in more detail below inconnection with FIGS. 26-27) at a free rotating joint 2029 of the shaft2008 to thereby rotate the end effector 2012 and (2) an articulationcontrol 2016 to effect rotational articulation of the end effector 2012about the articulation pivot 2014. In the illustrated embodiment, theend effector 2012 is configured to act as an endocutter for clamping,severing and stapling tissue, although in other embodiments, differenttypes of end effectors may be used, such as end effectors for othertypes of surgical instruments, such as graspers, cutters, staplers, clipappliers, access devices, drug/gene therapy devices, ultrasound, RF orlaser devices, etc.

The handle 2006 of the instrument 2010 may include a closure trigger2018 and a firing trigger 2020 for actuating the end effector 2012. Itwill be appreciated that instruments having end effectors directed todifferent surgical tasks may have different numbers or types of triggersor other suitable controls for operating the end effector 2012. The endeffector 2012 is shown separated from the handle 2006 by the preferablyelongate shaft 2008. The handle may comprise a control unit 2300(described below) in communication with a first element 2021 by way ofan electrical connection 2023. The electrical connection 2023 may be awired electrical connection such as an electrically conductive insulatedwire or may be a wireless electrical connection. The electricallyconductive insulated wire may be made of an electrically conductivepolymer and/or metal (e.g., copper) and may be sufficiently flexible sothat it could pass through the articulation control 2016, the rotationknob 2028, the free rotating joint 2029 and other components in thehandle 2006 of the instrument 2010 without being damaged by rotation.The first element 2021 may be disposed at a distal end of the shaft 2008prior to the articulation pivot 2014. A second element 2035 (shown inFIG. 25 below) may be disposed in the articulating end effector 2012 andis in wireless communication with the first element 2021. The operationof the first and second elements 2021, 2023 and the control unit 2300 isdescribed below. In one embodiment, a clinician or operator of theinstrument 2010 may articulate the end effector 2012 relative to theshaft 2008 by utilizing the articulation control 2016, as described inmore detail in U.S. patent application Ser. No. 11/329,020, filed Jan.10, 2006, entitled SURGICAL INSTRUMENT HAVING AN ARTICULATING ENDEFFECTOR, now U.S. Pat. No. 7,670,334, which is incorporated herein byreference.

The end effector 2012 includes in this example, among other things, astaple channel 2022 and a pivotally translatable clamping member, suchas an anvil 2024, which are maintained at a spacing that assureseffective stapling and severing of tissue clamped in the end effector2012. The handle 2006 includes a pistol grip 2026 towards which aclosure trigger 2018 is pivotally drawn by the clinician to causeclamping or closing of the anvil 2024 toward the staple channel 2022 ofthe end effector 2012 to thereby clamp tissue positioned between theanvil 2024 and channel 2022. The firing trigger 2020 is farther outboardof the closure trigger 2018. Once the closure trigger 2018 is locked inthe closure position, the firing trigger 2020 may rotate slightly towardthe pistol grip 2026 so that it can be reached by the operator using onehand. Then the operator may pivotally draw the firing trigger 2020toward the pistol grip 2026 to cause the stapling and severing ofclamped tissue in the end effector 2012. The '573 application describesvarious configurations for locking and unlocking the closure trigger2018. In other embodiments, different types of clamping members besidesthe anvil 2024 could be used, such as, for example, an opposing jaw,etc.

It will be appreciated that the terms “proximal” and “distal” are usedherein with reference to a clinician gripping the handle 2006 of theinstrument 2010. Thus, the end effector 2012 is distal with respect tothe more proximal handle 2006. It will be further appreciated that, forconvenience and clarity, spatial terms such as “vertical” and“horizontal” are used herein with respect to the drawings. However,surgical instruments are used in many orientations and positions, andthese terms are not intended to be limiting and absolute.

The closure trigger 2018 may be actuated first. Once the clinician issatisfied with the positioning of the end effector 2012, the clinicianmay draw back the closure trigger 2018 to its fully closed, lockedposition proximate to the pistol grip 2026. The firing trigger 2020 maythen be actuated. When the clinician removes pressure from the firingtrigger 2020, it returns to the open position (shown in FIGS. 23 and24). A release button 2030 on the handle 2006, and in this example, onthe pistol grip 2026 of the handle, when depressed may release thelocked closure trigger 2018.

FIG. 25 is an exploded view of the end effector 2012 according tovarious embodiments. As shown in the illustrated embodiment, the endeffector 2012 may include, in addition to the previously-mentionedchannel 2022 and anvil 2024, a cutting instrument 2032, a sled 2033, astaple cartridge 2034 that is removably seated in the channel 2022, anda helical screw shaft 2036. The second element 2035 may be coupled orformed integrally with a component of interest. The cutting instrument2032 may be, for example, a knife. The anvil 2024 may be pivotablyopened and closed at a pivot point 2025 connected to the proximate endof the channel 2022. The anvil 2024 may also include a tab 2027 at itsproximate end that is inserted into a component of the mechanicalclosure system (described further below) to open and close the anvil2024. When the closure trigger 2018 is actuated, that is, drawn in by auser of the instrument 2010, the anvil 2024 may pivot about the pivotpoint 2025 into the clamped or closed position. If clamping of the endeffector 2012 is satisfactory, the operator may actuate the firingtrigger 2020, which, as explained in more detail below, causes the knife2032 and sled 2033 to travel longitudinally along the channel 2022,thereby cutting tissue clamped within the end effector 2012. Themovement of the sled 2033 along the channel 2022 causes the staples ofthe staple cartridge 2034 to be driven through the severed tissue andagainst the closed anvil 2024, which turns the staples to fasten thesevered tissue. U.S. Pat. No. 6,978,921, entitled SURGICAL STAPLINGINSTRUMENT INCORPORATING AN E-BEAM FIRING MECHANISM, which isincorporated herein by reference, provides more details about suchtwo-stroke cutting and fastening instruments. The sled 2033, which maycomprise the second element 2035, may be part of the cartridge 2034,such that when the knife 2032 retracts following the cutting operation,the sled 2033 and the second element 2035 do not retract. The cartridge2034 could be made of a nonconductive material (such as plastic). In oneembodiment, the second element 2035 may be connected to or disposed inthe cartridge 2034, for example. In the illustrated embodiment, thesecond element 2035 may be attached to the sled 2033 in any suitablemanner and on any suitable portion thereof. In other embodiments, thesecond element 2035 may be embedded in the sled 2033 or otherwiseintegrally formed (e.g., co-molded) with the sled 2033. Accordingly, thelocation of the sled 2033 may be determined by detecting the location ofthe second element 2035. The second element 2035 may be formed ofvarious materials in various sizes and shapes and may be located atcertain predetermined distances from the first element 2021 to enablethe control unit 2300 to ascertain the type, presence and status of thestaple cartridge 2034.

It should be noted that although the embodiments of the instrument 2010described herein employ an end effector 2012 that staples the severedtissue, in other embodiments different techniques for fastening orsealing the severed tissue may be used. For example, end effectors thatuse RF energy or adhesives to fasten the severed tissue may also beused. U.S. Pat. No. 5,709,680, entitled ELECTROSURGICAL HEMOSTATICDEVICE, and U.S. Pat. No. 5,688,270, entitled ELECTROSURGICAL HEMOSTATICDEVICE WITH RECESSED AND/OR OFFSET ELECTRODES, which are incorporatedherein by reference, disclose cutting instruments that use RF energy tofasten the severed tissue. U.S. patent application Ser. No. 11/267,811,now U.S. Pat. No. 7,673,783, and U.S. patent application Ser. No.11/267,383, now U.S. Pat. No. 7,607,557, which are also incorporatedherein by reference, disclose cutting instruments that use adhesives tofasten the severed tissue. Accordingly, although the description hereinrefers to cutting/stapling operations and the like, it should berecognized that this is an exemplary embodiment and is not meant to belimiting. Other tissue-fastening techniques may also be used.

FIGS. 26 and 27 are exploded views and FIG. 28 is a side view of the endeffector 2012 and shaft 2008 according to various embodiments. As shownin the illustrated embodiment, the shaft 2008 may include a proximateclosure tube 2040 and a distal closure tube 2042 pivotably linked by apivot links 2044. The distal closure tube 2042 includes an opening 2045into which the tab 2027 on the anvil 2024 is inserted in order to openand close the anvil 2024. Disposed inside the closure tubes 2040, 2042may be a proximate spine tube 2046. Disposed inside the proximate spinetube 2046 may be a main rotational (or proximate) drive shaft 2048 thatcommunicates with a secondary (or distal) drive shaft 2050 via a bevelgear assembly 2052. In the illustrated embodiment, the first element2021 may be a coil disposed about the proximate spine tube 2046 (e.g.,as shown in FIGS. 26 and 27). In a wired electrical connectionconfiguration, the first element 2021 may be connected to the controlunit 2300 by way of the wired electrical connection 2023, which maycomprise lengths of wire forming the coil. The lengths of wire may beprovided along the proximate spine tube 2046 to connect to the controlunit 2300. In a wireless electrical connection configuration, a wire isnot necessary and the electrical connection 2023 to the control unit2300 is a wireless electrical connection. In one embodiment, the firstelement 2021 may be contained within the proximate spine tube 2046(e.g., as shown in FIG. 28). In either case, the first element 2021 iselectrically isolated from the proximate spine tube 2046.

The secondary drive shaft 2050 is connected to a drive gear 2054 thatengages a proximate drive gear 2056 of the helical screw shaft 2036. Thevertical bevel gear 2052 b may sit and pivot in an opening 2057 in thedistal end of the proximate spine tube 2046. A distal spine tube 2058may be used to enclose the secondary drive shaft 2050 and the drivegears 2054, 2056. Collectively, the main drive shaft 2048, the secondarydrive shaft 2050, and the articulation assembly (e.g., the bevel gearassembly 2052 a-c), are sometimes referred to herein as the “main driveshaft assembly.” Components of the main drive shaft assembly (e.g., thedrive shafts 2048, 2050) may be made of a nonconductive material (suchas plastic).

A bearing 2038, positioned at a distal end of the staple channel 2022,receives the helical drive screw 2036, allowing the helical drive screw2036 to freely rotate with respect to the channel 2022. The helicalscrew shaft 2036 may interface a threaded opening (not shown) of theknife 2032 such that rotation of the shaft 2036 causes the knife 2032 totranslate distally or proximately (depending on the direction of therotation) through the staple channel 2022. Accordingly, when the maindrive shaft 2048 is caused to rotate by actuation of the firing trigger2020 (as explained in more detail below), the bevel gear assembly 2052a-c causes the secondary drive shaft 2050 to rotate, which in turn,because of the engagement of the drive gears 2054, 2056, causes thehelical screw shaft 2036 to rotate, which causes the knife 2032 totravel longitudinally along the channel 2022 to cut any tissue clampedwithin the end effector. The sled 2033 may be made of, for example,plastic, and may have a sloped distal surface. As previously discussed,the second element 2035 may be attached to the sled 2033 in any suitablemanner to determine the status, location and type of the sled 2033and/or the staple cartridge 2034. As the sled 2033 traverses the channel2022, the sloped forward surface may push up or drive the staples in thestaple cartridge 2034 through the clamped tissue and against the anvil2024. The anvil 2024 turns the staples, thereby stapling the severedtissue. When the knife 2032 is retracted, the knife 2032 and sled 2033may become disengaged, thereby leaving the sled 2033 at the distal endof the channel 2022.

According to various embodiments, as shown FIGS. 29-32, the surgicalinstrument may include a battery 2064 in the handle 2006. Theillustrated embodiment provides user-feedback regarding the deploymentand loading force of the cutting instrument in the end effector 2012. Inaddition, the embodiment may use power provided by the user inretracting the firing trigger 2018 to power the instrument 2010 (aso-called “power assist” mode). As shown in the illustrated embodiment,the handle 2006 includes exterior lower side pieces 2059, 2060 andexterior upper side pieces 2061, 2062 that fit together to form, ingeneral, the exterior of the handle 2006. The handle pieces 2059-2062may be made of an electrically nonconductive material, such as plastic.A battery 2064 may be provided in the pistol grip portion 2026 of thehandle 2006. The battery 2064 powers a motor 2065 disposed in an upperportion of the pistol grip portion 2026 of the handle 2006. The battery2064 may be constructed according to any suitable construction orchemistry including, for example, a Li-ion chemistry such as LiCoO₂ orLiNiO₂, a Nickel Metal Hydride chemistry, etc. According to variousembodiments, the motor 2065 may be a DC brushed driving motor having amaximum rotation of, approximately, 5000 to 100,000 RPM. The motor 2065may drive a 90° bevel gear assembly 2066 comprising a first bevel gear2068 and a second bevel gear 2070. The bevel gear assembly 2066 maydrive a planetary gear assembly 2072. The planetary gear assembly 2072may include a pinion gear 2074 connected to a drive shaft 2076. Thepinion gear 2074 may drive a mating ring gear 2078 that drives a helicalgear drum 2080 via a drive shaft 20082. A ring 2084 may be threaded onthe helical gear drum 2080. Thus, when the motor 2065 rotates, the ring2084 is caused to travel along the helical gear drum 2080 by means ofthe interposed bevel gear assembly 2066, planetary gear assembly 2072and ring gear 2078.

The handle 2006 may also include a run motor sensor 2110 incommunication with the firing trigger 2020 to detect when the firingtrigger 2020 has been drawn in (or “closed”) toward the pistol gripportion 2026 of the handle 2006 by the operator to thereby actuate thecutting/stapling operation by the end effector 2012. The sensor 2110 maybe a proportional sensor such as, for example, a rheostat or variableresistor. When the firing trigger 2020 is drawn in, the sensor 2110detects the movement, and sends an electrical signal indicative of thevoltage (or power) to be supplied to the motor 2065. When the sensor2110 is a variable resistor or the like, the rotation of the motor 2065may be generally proportional to the amount of movement of the firingtrigger 2020. That is, if the operator only draws or closes the firingtrigger 2020 in a little bit, the rotation of the motor 2065 isrelatively low. When the firing trigger 2020 is fully drawn in (or inthe fully closed position), the rotation of the motor 2065 is at itsmaximum. In other words, the harder the user pulls on the firing trigger2020, the more voltage is applied to the motor 2065, causing greaterrates of rotation.

The handle 2006 may include a middle handle piece 2104 adjacent to theupper portion of the firing trigger 2020. The handle 2006 also maycomprise a bias spring 2112 connected between posts on the middle handlepiece 2104 and the firing trigger 2020. The bias spring 2112 may biasthe firing trigger 2020 to its fully open position. In that way, whenthe operator releases the firing trigger 2020, the bias spring 2112 willpull the firing trigger 2020 to its open position, thereby removingactuation of the sensor 2110, thereby stopping rotation of the motor2065. Moreover, by virtue of the bias spring 2112, any time a usercloses the firing trigger 2020, the user will experience resistance tothe closing operation, thereby providing the user with feedback as tothe amount of rotation exerted by the motor 2065. Further, the operatorcould stop retracting the firing trigger 2020 to thereby remove forcefrom the sensor 2110, to thereby stop the motor 2065. As such, the usermay stop the deployment of the end effector 2012, thereby providing ameasure of control of the cutting/fastening operation to the operator.

The distal end of the helical gear drum 2080 includes a distal driveshaft 2120 that drives a ring gear 2122, which mates with a pinion gear2124. The pinion gear 2124 is connected to the main drive shaft 2048 ofthe main drive shaft assembly. In that way, rotation of the motor 2065causes the main drive shaft assembly to rotate, which causes actuationof the end effector 2012, as described above.

The ring 2084 threaded on the helical gear drum 2080 may include a post2086 that is disposed within a slot 2088 of a slotted arm 2090. Theslotted arm 2090 has an opening 2092 at its opposite end 2094 thatreceives a pivot pin 2096 that is connected between the handle exteriorside pieces 2059, 2060. The pivot pin 2096 is also disposed through anopening 2100 in the firing trigger 2020 and an opening 2102 in themiddle handle piece 2104.

In addition, the handle 2006 may include a reverse motor (orend-of-stroke sensor) 2130 and a stop motor (or beginning-of-stroke)sensor 2142. In various embodiments, the reverse motor sensor 2130 maybe a limit switch located at the distal end of the helical gear drum2080 such that the ring 2084 threaded on the helical gear drum 2080contacts and trips the reverse motor sensor 2130 when the ring 2084reaches the distal end of the helical gear drum 2080. The reverse motorsensor 2130, when activated, sends a signal to the control unit whichsends a signal to the motor 2065 to reverse its rotation direction,thereby withdrawing the knife 2032 of the end effector 2012 followingthe cutting operation.

The stop motor sensor 2142 may be, for example, a normally-closed limitswitch. In various embodiments, it may be located at the proximate endof the helical gear drum 2080 so that the ring 2084 trips the switch2142 when the ring 2084 reaches the proximate end of the helical geardrum 2080.

The handle 2006 also may comprise the control unit 2300. The controlunit 2300 may be powered through the battery 2064 with the addition of aconditioning circuit (not shown). The control unit 2300 is coupled tothe first element 2021 by an electrical connection 2023. As previouslydiscussed, the electrical connection 2023 may be a wired electricalconnection or a wireless electrical connection.

In operation, when an operator of the instrument 2010 pulls back thefiring trigger 2020, the sensor 2110 detects the deployment of thefiring trigger 2020 and sends a signal to the control unit which sends asignal to the motor 2065 to cause forward rotation of the motor 2065 at,for example, a rate proportional to how hard the operator pulls back thefiring trigger 2020. The forward rotation of the motor 2065 in turncauses the ring gear 2078 at the distal end of the planetary gearassembly 2072 to rotate, thereby causing the helical gear drum 2080 torotate, causing the ring 2084 threaded on the helical gear drum 2080 totravel distally along the helical gear drum 2080. The rotation of thehelical gear drum 2080 also drives the main drive shaft assembly asdescribed above, which in turn causes deployment of the knife 2032 inthe end effector 2012. That is, the knife 2032 and the sled 2033 arecaused to traverse the channel 2022 longitudinally, thereby cuttingtissue clamped in the end effector 2012. Also, the stapling operation ofthe end effector 2012 is caused to happen in embodiments where astapling-type end effector is used.

By the time the cutting/stapling operation of the end effector 2012 iscomplete, the ring 2084 on the helical gear drum 2080 will have reachedthe distal end of the helical gear drum 2080, thereby causing thereverse motor sensor 2130 to be tripped, which sends a signal to thecontrol unit which sends a signal to the motor 2065 to cause the motor2065 to reverse its rotation. This in turn causes the knife 2032 toretract, and also causes the ring 2084 on the helical gear drum 2080 tomove back to the proximate end of the helical gear drum 2080.

The middle handle piece 2104 includes a backside shoulder 2106 thatengages the slotted arm 2090 as best shown in FIGS. 30 and 31. Themiddle handle piece 2104 also has a forward motion stop 2107 thatengages the firing trigger 2020. The movement of the slotted arm 2090 iscontrolled, as explained above, by rotation of the motor 2065. When theslotted arm 2090 rotates CCW as the ring 2084 travels from the proximateend of the helical gear drum 2080 to the distal end, the middle handlepiece 2104 will be free to rotate CCW. Thus, as the user draws in thefiring trigger 2020, the firing trigger 2020 will engage the forwardmotion stop 2107 of the middle handle piece 2104, causing the middlehandle piece 2104 to rotate CCW. Due to the backside shoulder 2106engaging the slotted arm 2090, however, the middle handle piece 2104will only be able to rotate CCW as far as the slotted arm 2090 permits.In that way, if the motor 2065 should stop rotating for some reason, theslotted arm 2090 will stop rotating, and the user will not be able tofurther draw in the firing trigger 2020 because the middle handle piece2104 will not be free to rotate CCW due to the slotted arm 2090.

Components of an exemplary closure system for closing (or clamping) theanvil 2024 of the end effector 2012 by retracting the closure trigger2018 are also shown in FIGS. 29-32. In the illustrated embodiment, theclosure system includes a yoke 2250 connected to the closure trigger2018 by a pin 2251 that is inserted through aligned openings in both theclosure trigger 2018 and the yoke 2250. A pivot pin 2252, about whichthe closure trigger 2018 pivots, is inserted through another opening inthe closure trigger 2018 which is offset from where the pin 2251 isinserted through the closure trigger 2018. Thus, retraction of theclosure trigger 2018 causes the upper part of the closure trigger 2018,to which the yoke 2250 is attached via the pin 2251, to rotate CCW. Thedistal end of the yoke 2250 is connected, via a pin 2254, to a firstclosure bracket 2256. The first closure bracket 2256 connects to asecond closure bracket 2258. Collectively, the closure brackets 2256,2258 define an opening in which the proximate end of the proximateclosure tube 2040 (FIG. 26) is seated and held such that longitudinalmovement of the closure brackets 2256, 2258 causes longitudinal motionby the proximate closure tube 2040. The instrument 2010 also includes aclosure rod 2260 disposed inside the proximate closure tube 2040. Theclosure rod 2260 may include a window 2261 into which a post 2263 on oneof the handle exterior pieces, such as exterior lower side piece 2059 inthe illustrated embodiment, is disposed to fixedly connect the closurerod 2260 to the handle 2006. In that way, the proximate closure tube2040 is capable of moving longitudinally relative to the closure rod2260. The closure rod 2260 may also include a distal collar 2267 thatfits into a cavity 2269 in proximate spine tube 2046 and is retainedtherein by a cap 2271 (FIG. 26).

In operation, when the yoke 2250 rotates due to retraction of theclosure trigger 2018, the closure brackets 2256, 2258 cause theproximate closure tube 2040 to move distally (i.e., away from the handleend of the instrument 2010), which causes the distal closure tube 2042to move distally, which causes the anvil 2024 to rotate about the pivotpoint 2025 into the clamped or closed position. When the closure trigger2018 is unlocked from the locked position, the proximate closure tube2040 is caused to slide proximately, which causes the distal closuretube 2042 to slide proximately, which, by virtue of the tab 2027 beinginserted in the window 2045 of the distal closure tube 2042, causes theanvil 2024 to pivot about the pivot point 2025 into the open orunclamped position. In that way, by retracting and locking the closuretrigger 2018, an operator may clamp tissue between the anvil 2024 andchannel 2022, and may unclamp the tissue following the cutting/staplingoperation by unlocking the closure trigger 2018 from the lockedposition.

The control unit 2300 (described further below) may receive the outputsfrom end-of-stroke and beginning-of-stroke sensors 2130, 2142 and therun-motor sensor 2110, and may control the motor 2065 based on theinputs. For example, when an operator initially pulls the firing trigger2020 after locking the closure trigger 2018, the run-motor sensor 2110is actuated. If the staple cartridge 2034 is present in the end effector2012, a cartridge lockout sensor (not shown) may be closed, in whichcase the control unit may output a control signal to the motor 2065 tocause the motor 2065 to rotate in the forward direction. When the endeffector 2012 reaches the end of its stroke, the reverse motor sensor2130 will be activated. The control unit may receive this output fromthe reverse motor sensor 2130 and cause the motor 2065 to reverse itsrotational direction. When the knife 2032 is fully retracted, the stopmotor sensor switch 2142 is activated, causing the control unit to stopthe motor 2065.

In other embodiments, rather than a proportional-type sensor 2110, anon-off type sensor may be used. In such embodiments, the rate ofrotation of the motor 2065 would not be proportional to the forceapplied by the operator. Rather, the motor 2065 would generally rotateat a constant rate. But the operator would still experience forcefeedback because the firing trigger 2020 is geared into the gear drivetrain.

The instrument 2010 may include a number of sensor elements in the endeffector 2012 for sensing various conditions related to the end effector2012, such as sensor elements for determining the status of the staplecartridge 2034 (or other type of cartridge depending on the type ofsurgical instrument), the progress of the stapler during closure andfiring, etc. The sensor elements may be passively powered by inductivelycoupled signals, as described in commonly assigned U.S. patentapplication Ser. No. 11/651,715, entitled SURGICAL INSTRUMENT WITHWIRELESS COMMUNICATION BETWEEN CONTROL UNIT AND SENSOR TRANSPONDERS, nowU.S. Pat. No. 8,652,120, which is incorporated herein by reference. Inother embodiments, the sensor elements reflect or scatter incidentelectromagnetic energy or power up in response to the interrogationsignal and transmit echo response pulses or signals that may be coupledback to the control unit 2300 for processing. In other embodiments, thesensor elements may be powered by the minute electrical current inducedin the sensor element itself or an antenna coupled to the sensor elementby the incoming incident electromagnetic energy (e.g., the RF carrier ofthe interrogation signal) transmitted by the control unit 2300. Thesesensor elements may comprise any arrangement of electrical conductors totransmit, receive, amplify, encode, scatter and/or reflectelectromagnetic energy waves of any suitable predetermined frequency(e.g., wavelength [λ]), having a suitable predetermined pulse width thatmay be transmitted over a suitable predetermined time period. Thepassive sensor elements may comprise any suitable arrangement ofresistive, inductive, and/or capacitive elements. The active sensorelements may comprise semiconductors such as transistors, integratedcircuits, processors, amplifiers and/or any combination of these activeelements. For succinctness the passive and/or active sensor elements arereferred to hereinafter as the first element 2021 and the second element2035. The first element 2021 may be in wired or wireless communicationwith the control unit 2300, which, as previously discussed, may behoused in the handle 2006 of the instrument 2010, for example, as shownbelow in FIG. 33. The first element 2021 is in wireless communicationwith the second element 2035.

FIG. 33 illustrates a schematic block diagram of one embodiment of thecontrol unit 2300. According to various embodiments, the control unit2300 may comprise a processor 2306 and one or more memory units 2308. Byexecuting instruction code stored in the memory 2308, the processor 2306may control various components of the instrument 2010, such as the motor2065 or a user display (not shown), based on inputs received from theone or more end effector sensor element(s) and/or other sensor elementslocated throughout the instrument 2010 (such as the run-motor sensor2110, the end-of-stroke sensor 2130, and the beginning-of-stroke sensor2142, for example). The control unit 2300 may be powered by the battery2064 during surgical use of the instrument 2010. The control unit 2300may be coupled to the first element 2021 over the electrical connection2023 and may communicate with the second element 2035, as described inmore detail below. The control unit 2300 may comprise a transmitter 2320and a receiver 2322. The first element 2021 may be coupled to thetransmitter 2320 to transmit an output interrogation signal or may becoupled to the receiver 2322 to receive an echo response signal inaccordance with the operation of a switch 2324.

The switch 2324 may operate under the control of the processor 2306, thetransmitter 2320 or the receiver 2322 or any combination thereof toplace the control unit 2300 either in transmitter or receiver mode. Intransmitter mode, the switch 2324 couples the first element 2021 to thetransmitter 2320 and thus the first element 2021 acts as a transmittingantenna. An encoder 2316 encodes the output interrogation signal to betransmitted, which is then modulated by a modulator 2318. An oscillator2326 coupled to the modulator 2318 sets the operating frequency for theoutput signal to be transmitted. In receiver mode, the switch 2324couples the first element 2021 to the receiver 2322. Accordingly, thefirst element 2021 acts as a receiving antenna and receives inputsignals from the other sensor elements (e.g., the second element 2035).The received input signals may be demodulated by a demodulator 2310 anddecoded by a decoder 2312. The input signals may comprise echo responsesignals from one or more of the sensor elements (e.g., the secondelement 2035). The echo response signals may comprise informationassociated with the location, type, presence and/or status of variouscomponents located in the end effector 2012 or in other location in theinstrument 2010. The echo signals, for example, may comprise signalsreflected by the second element 2035, which may be attached to the sled2033, the staple cartridge 2034 or any other component located in theend effector 2012 or may be located on any component of interest on anyportion of the instrument 2010. The echo signal data reflected from thesecond element 2035 may be used by the processor 2306 to control variousaspects of the instrument 2010.

To transmit an output signal from the first element 2021 to the secondelement 2035, the control unit 2300 may employ the encoder 2316 forencoding the output signals and the modulator 2318 for modulating theoutput signals according to a predetermined modulation scheme. Aspreviously discussed, in transmitter mode, the first element 2021 iscoupled to the transmitter 2320 through the switch 2324 and acts as atransmitting antenna. The encoder 2316 may comprise a timing unit togenerate timing pulses at a predetermined suitable pulse repetitionfrequency. These timing pulses may be applied to the modulator 2318 totrigger the transmitter at precise and regularly occurring instants oftime. Thus, in one embodiment, the modulator 2318 may producerectangular pulses of known pulse duration to switch the oscillator 2326on and off. In accordance with the modulation scheme, the oscillator2326 produces short duration pulses of a predetermined power andfrequency (or wavelength λ) set by the oscillator 2326. The pulserepetition frequency may be determined by the encoder 2312 and the pulseduration may be determined by the modulator 2318. The switch 2324 undercontrol of the control unit 2300 automatically connects the transmitter2320 to the first element 2021 for the duration of each output pulse. Intransmission mode, the first element 2021 radiates the transmitter 2320output pulse signal and picks up or detects the reflected echo signalsfor application to the receiver 2322. In receiver mode, the switch 2324connects the first element 2021 to the receiver 2322 for the intervalsbetween transmission pulses. The receiver 2322 receives echo signals ofthe transmitted pulse output signals that may be reflected from one ormore sensor elements located on the instrument such as the secondelement 2035 attached to the sled 2033. The receiver 2322 amplifies theecho signals and presents them to the demodulator 2310 in suitable form.Subsequently, the demodulated echo signals are provided to the decoder2312 where they are correlated with the transmitted output pulse signalsto determine the location, type, presence and/or status of variouscomponents located in the end effector 2012. In addition, the distancebetween the first and second elements 2021, 2035 may be determined.

The control unit 2300 may communicate with the first element 2021 usingany suitable wired or wireless communication protocol and any suitablefrequency (e.g., an ISM band). The control unit 2300 may transmit outputpulse signals in various frequency ranges. Although in the illustratedembodiment, only the first element 2021 is shown to perform thetransmission and reception functions, in other embodiments the controlunit 2300 may comprise separate receiving and transmitting elements, forexample.

According to various embodiments, the control unit 2300 may beimplemented using integrated and/or discrete hardware elements, softwareelements, or a combination of both. Examples of integrated hardwareelements may include processors, microprocessors, microcontrollers,integrated circuits, application specific integrated circuits (ASIC),programmable logic devices (PLD), digital signal processors (DSP), fieldprogrammable gate arrays (FPGA), logic gates, registers, semiconductordevices, chips, microchips, chip sets, microcontroller, system-on-chip(SoC) or system-in-package (SIP). Examples of discrete hardware elementsmay include circuits, circuit elements (e.g., logic gates, field effecttransistors, bipolar transistors, resistors, capacitors, inductors,relay and so forth). In other embodiments, the control unit 2300 may beembodied as a hybrid circuit comprising discrete and integrated circuitelements or components on one or more substrates. In variousembodiments, the control unit 2300 may provide a digital (e.g., on/off,high/low) output and/or an analog output to a motor control unit. Themotor control unit also may be embodied using elements and/or componentssimilar to the control unit 2300. The motor control unit may be used tocontrol the motor 2065 in response to the radiated echo response signalsfrom the one or more passive and/or active sensor elements.

Referring back to FIGS. 23-28, in one embodiment, the first element 2021may be an inductive element (e.g., a first coil) coupled to the controlunit 2300 by the wired electrical connection 2023. The wired electricalconnection 2023 may be an electrically conductive insulated wire. Thesecond element 2035 also may be an inductive element (e.g., a secondcoil) embedded, integrally formed with or otherwise attached to the sled2033. The second element 2035 is wirelessly coupled to the first element2021. The first element 2021 is preferably electrically insulated fromthe conductive shaft 2008. The second element 2035 is preferablyelectrically insulated from the sled 2033 and other components locatedin the staple cartridge 2034 and/or the staple channel 2022. The secondelement 2035 receives the output pulse signal transmitted by the firstelement 2021 and reflects or scatters the electromagnetic energy in theform of an echo signal. By varying the material, size, shape andlocation of the second element 2035 relative to the first element 2021,the control unit 2300 can determine the location, type, presence and/orstatus of various components located in the end effector 2012 bydecoding the echo signals reflected therefrom.

FIG. 34 is a schematic diagram 2400 illustrating the operation of oneembodiment of the control unit 2300 in conjunction with the first andsecond elements 2021, 2035. The following description also referencesFIG. 33. The first element 2021 is coupled to the control unit 2300 by achannel, e.g., the electrical connection 2023. The electrical connection2023 may be a wired or wireless channel. As previously discussed, thefirst element 2021 wirelessly interrogates or illuminates the secondelement 2035 by transmitting an interrogation signal in the form of oneor more interrogation pulses 2402. The interrogation pulses 2402 may beof a suitable predetermined frequency f as may be determined by theoscillator 2326. The interrogation pulses 2402 may have a predeterminedpulse width PW as may be determined by the modulator 2318 and may betransmitted at a pulse repetition rate T as may be determined by theencoder 2316. The transmitted interrogation pulses 2402 that areincident upon (e.g., strike or illuminate) the second element 2035 isreflected or scattered by the second element 2035 in the form of echoresponse pulses 2404. The echo response pulses 2404 are electromagneticenergy reflections of the interrogation pulses 2402 incident upon thesecond element 2021, but much weaker in signal strength. Aftertransmitting the interrogation pulses 2402, the first element 2021listens for the echo response pulses 2404 and couples the echo responsepulses 2402 to the control unit 2300 in a suitable form. The demodulator2310 receives the weak echo response pulses 2404 and amplifies anddemodulates them. The decoder 2312 and the processor 2306 process thereceived echo response pulses 2404 to extract information therefrom. Theprocessor 2306 (or other logic) may be programmed to ascertain variousproperties associated with the end effector 2012 and components inaccordance with the received echo response pulses 2404.

The frequency f, PW and T of the echo response pulses 2404 may be thesame as the interrogation pulses 2402. In various embodiments, thefrequency f, PW and T of the echo response pulses 2404 may be differentthan the interrogation pulses 2402. In one embodiment, the frequency f,for example, of the echo response pulses 2404 may be a harmonicfrequency of the interrogation pulse 2402 frequency. The amount ofreflected electromagnetic energy in the echo response pulses 2404depends upon the material, shape and size of the second element 2035.The amount of reflected electromagnetic energy in the echo responsepulses 2404 also depends upon the distance D between the first element2021 and the second element 2035.

The material that the second element 2035 is formed of may determine theamount of reflected energy. For example, a metal object will reflectmore energy than an object of the same size and shape made of wood,plastic, etc. In general, the better the electrical conductiveproperties of the material the greater is the reflection. The shape ofthe second element 2035 also may determine how the energy is reflectedor scattered. For example, if the second element 2035 has a flat sidefacing the first element 2021, the second element 2035 may reflect moreenergy back towards the first element 2021. A circular object mayreflect or scatter the energy in the various directions normal to thesurface struck by the incident electromagnetic energy and an object withirregularities will scatter the incident electromagnetic energy morerandomly. The size of the second element 2021 also may determine theamount of reflected energy. For example, a larger second element 2035will reflect more energy than a smaller second element 2035 of the samematerial and shape and at the same distance D from the first element2021. It will be appreciated that the second element 2035 should have acertain minimum size relative to the wavelength (λ) of the radiatedelectromagnetic energy of the interrogation pulses 2402 to producepractical reflected echo response pulses 2404. For example, the size ofthe second element 2035 may be equal to or greater than about a quarterof the wavelength (λ/4) of the electromagnetic energy of theinterrogation pulses 2402. The wavelength λ of the transmittedinterrogation pulses 2402 is related to the frequency f in accordancewith the equation: λ=c/f; where c is the speed of light and f is thesignal frequency. Therefore, to detect small objects the wavelength λmust be small and thus the frequency f must be high. Any suitablepredetermined frequency f may be selected to accommodate the size of thesecond element 2035 to be detected. Accordingly, the size of the secondelement 2035 may be selected to be greater than or equal to λ/4 (orc/4f), for example, once the interrogation pulse 2402 frequency isdetermined. As previously discussed, the amount of energy reflected bythe second element 2035 also depends on the distance D between the firstelement 2021 and the second element 2035.

Accordingly, the material, shape and size of the second element 2035 andthe relative distance D between it and the first element 2021 may beselected to generate unique echo response pulses 2404 that may beindicative of a desired measurement associated with the second element2035. For example, unique echo response pulses 2404 may indicate thelocation, type, presence and/or status of various components and/orsub-components disposed on the surgical instrument 2010. Especially thevarious components and sub-components disposed in the end effector 2012portion of the surgical instrument 2010 subsequent to the articulationpivot 2014. The echo response pulses 2404 also may be used to determinethe distance D between the first element 2021 and the second element2035. In this manner, by integrating the second element 2035 orattaching it to a components of interest, such as the sled 2033, theecho response pulses 2404 may be processed by the control unit 2300 toextract and provide information associated with the component ofinterest, such as the location, type, presence and/or status of the sled2033, the staple cartridge 2034, and so on. This arrangement mayeliminate the need to transmit or provide power over a wired connectionto the second element 2035 and may be a cost effective solution toproviding various sensor elements on the surgical instrument 2010.

In one embodiment, where the second element 2035 is an active sensorelement, as previously discussed, the first element 2021 wirelesslyinterrogates or illuminates the second element 2035 by transmitting aninterrogation signal in the form of one or more interrogation pulses2402. The electromagnetic energy in the interrogation pulses 2402 arecoupled by the sensor element 2035 and serve to power-up the sensorelement 2035. Once powered-up, the sensor element 2035 transmits theecho response pulses 2404 back to the control unit 2300.

In one embodiment, the status of the staple cartridge 2034 and thelocation of the sled 2033 may be determined by transmitting theinterrogation pulse 2402 and listening for an echo response pulse 2404.As previously discussed, the first and second elements 2021, 2035 may bepassive sensors or electromagnetic elements (which may compriseresistive, inductive and capacitive elements or any combinationthereof). In one embodiment, the first element 2021 may be an inductancein the form of a primary coil located at the distal end of the shaft2008 (as shown in FIGS. 23, 24, 26-28). The second element 2035 may bean inductive element in the form of a secondary coil located in the sled2033 (as shown in FIGS. 25, 27, 28). The first element 2021 “pings” ortransmits interrogation pulses 2402. The echo response pulses 2404reflected by the second element 2035 may be indicative of the presenceof the sled 2033 in the staple channel 2022, its distance from the firstelement 2021 or its location longitudinally along the staple channel2022. In this manner, the instrument 2010 can determine the presence orstatus of the staple cartridge 2034 or the sled 2033 in the end effector2012 or the longitudinal location of the sled 2033 along the staplechannel 2022. This information may be used to determine the loadedstatus of the staple cartridge 2034, for example. Further the secondelement 2035 may be formed of different materials, in different shapesor sizes to produce a unique echo response pulse 2404 that is indicativeof the instrument 2010 type or presence of the staple cartridge 2034within the end effector 2012. This eliminates the need to include anypowered memory or sensor elements in the end effector 2012 toelectronically determine the type, presence or status of the staplecartridge 2034 in the end effector 2012.

In another embodiment, the second element 2035 may be attached to thesled 2033 and the echo response pulse 2404 may be used to determinewhether the sled 2033 is located in a first position at the proximal endof the staple channel 2022 or a second position at the distal end of thestaple channel 2022 or in any intermediate positions therebetween. Thecontrol unit 2300 may be determine the position of the sled 2033 basedon the elapsed time between transmitting the interrogation pulse 2402and receiving the echo response pulse 2404. If the sled 2033 is in thefirst position the echo response pulse 2404 is received sooner than ifthe sled 2033 was located at the second position or any positiontherebetween. For example, as the sled 2033 moves longitudinally alongthe staple channel 2022 the response time of the received echo responsepulse 2404 relative to the transmitted interrogation pulse 2402increases. This information may be used by the control unit 2300 todetermine the intermediate location of the sled 2033 in the channel 2022and provide some measure of control of the cutting/fastening operation,such as inhibiting the cutting/fastening operation if the sled 2033, orother component, is not in a predetermined location.

In yet another embodiment, the control unit 2300 may provide somemeasure of control of the cutting/fastening operation based on whetheror not an echo response pulse 2404 is received within a predeterminedtime period. For example, if an echo response pulse 2404 is receivedwithin the predetermined period, the control unit 2300 determines thatthe sled 2033 in located in the proximate end on the staple channel2022. In contrast, if the no echo response pulse 2404 is received withinthe predetermined period, the control unit 2300 determines that the sled2033 has moved away from the proximate end to the distal end of thestaple channel 2022 (e.g., the instrument has been fired). In thismanner, if no echo response pulse 2404 is received, the control unit2300 may determine either that the staple cartridge 2034 has been firedand, therefore, the sled 2033 has moved away longitudinally from theproximate end of the staple channel 2022 or that there is no staplecartridge 2034 loaded and, therefore, prevents the instrument 2010(e.g., a surgical stapler) from firing.

Although the first element 2021 is shown disposed at one end of theelongate shaft 2008 near the articulation pivot 2014, the first element2021 may be disposed anywhere along the elongate shaft 2008 and/or inthe handle 2006 in suitable wireless or wired communication with thesecond element 2035.

FIG. 35 illustrates one embodiment of the surgical instrument 2010comprising the first element 2021 located in the free rotating joint2029 portion of the shaft 2008. The following description alsoreferences FIGS. 25, 27, 28 and 34. The first element 2021 is coupled tothe control unit 2300 via the electrical connection 2023. Additionalelements may be employed, for example, when the surgical instrument 2010has numerous complex mechanical joints and where it would be difficultto maintain a direct wired connection. In such cases, inductivecouplings may be used to span each such joint. For example, inductivecouplers may be used on both sides of the rotary joint 2029 and bothsides of the articulation pivot 2014, with an inductive element on thedistal side of the rotary joint 2029 connected by an electricalconnection to another inductive element on the proximate side of thearticulation pivot 2014. Accordingly, a third element 2328 and a fourthelement 2330 may be disposed on the shaft 2008. These elements 2328,2330 may disposed anywhere along the shaft 2008. The third element 2328may be disposed on the proximal end of the shaft 2008 just prior to thearticulation control 2016. The fourth element 2330 may be disposed onthe distal end of the shaft 2008 just prior to the articulation pivot2014. The third and fourth elements 2328, 2330 may be coupled by anelectrical connection 2332, which may be a wired or a wirelesselectrical connection. The second element 2035 is disposed or attachedto a component of interest in the end effector 2012. The third element2328 is wirelessly coupled to the first element 2021 and receivesinterrogation pulses 2402 therefrom. The third element 2328 transmitsthe interrogation pulse 2402 along the electrical connection 2332 to thefourth element 2330. The fourth element 2330 wirelessly couples theinterrogation pulse 2402 to the second element 2035. The echo responsepulses 2404 are transmitted back to the first element 2021 in reverseorder. For example, the echo response pulse 2404 is wirelessly coupledto the fourth element 2330, is relayed to the third element 2328 via theelectrical connection 2332 and is then wirelessly coupled to the firstelement 2021. Similarly to the first and second elements 2021, 2035, thethird and fourth elements 2328, 2330 may be formed of passive and/oractive sensor elements (e.g., resistive, inductance, capacitive and/orsemiconductor elements). In one embodiment, the third and fourthelements 2328, 2330 may be passive coils formed of various materials andin various shapes and sizes or may comprise semiconductor elements suchas transistors to operate in active mode.

FIG. 36 illustrates one embodiment of the surgical instrument 2010comprising sensor elements disposed at various locations on the shaft.For example, the first element 2021 may be disposed on the proximate endof the shaft 2008 just prior to the articulation control 2016. The firstelement 2021 is wirelessly coupled to the control unit 2300 via wirelesselectrical connection 2023. The third element 2328 and the fourthelement 2330 are disposed along the shaft 2008 subsequent to thearticulation control 2016 and prior to the articulation pivot 2014. Thethird element 2328 may be disposed on the proximate end of the shaft2008 subsequent to the articulation control 2016 and the fourth element2330 may be disposed on the distal end of the elongate shaft 2008 priorto the articulation pivot 2014. The third and fourth elements 2328, 2330are coupled by the electrical connection 2332, which may be a wired or awireless electrical connection. As previously discussed, the secondelement 2035 may be disposed on a component of interest located in theend effector 2012. The third element 2328 is wirelessly coupled to thefirst element 2021 and receives the interrogation pulses 2402 therefrom.The third element 2328 transmits the interrogation pulse 2402 along theelectrical connection 2332 to the fourth element 2330. The fourthelement 2330 wirelessly couples the interrogation pulse 2402 to thesecond element 2035. The echo response pulses 2404 are transmitted backto the first element 2021 in reverse order. For example, the echoresponse pulse 2404 is wirelessly coupled to the fourth element 2330, isrelayed to the third element 2328 via the electrical connection 2332 andis wirelessly coupled to the first element 2021 thereafter.

FIG. 37 illustrates one embodiment of the instrument 2010 where theshaft serves as part of the antenna for the control unit 2300.Accordingly, the shaft 2008 of the instrument 2010, including forexample, the proximate closure tube 2040 and the distal closure tube2042, may collectively serve as part of an antenna for the control unit2300 by radiating the interrogation pulses 2402 to the second element2035 and receiving the echo response pulses 2404 reflected from thesecond element 2035. That way, signals to and from the control unit 2300and the second element 2035 disposed in the end effector 2012 may betransmitted via the shaft 2008 of the instrument 2010.

The proximate closure tube 2040 may be grounded at its proximate end bythe exterior lower and upper side pieces 2059-2062, which may be made ofa nonelectrically conductive material, such as plastic. The drive shaftassembly components (including the main drive shaft 2048 and secondarydrive shaft 2050) inside the proximate and distal closure tubes 2040,2042 may also be made of a nonelectrically conductive material, such asplastic. Further, components of the end effector 2012 (such as the anvil2024 and the channel 2022) may be electrically coupled to (or in director indirect electrical contact with) the distal closure tube 2042 suchthat they may also serve as part of the antenna. Further, the secondelement 2035 may be positioned such that it is electrically insulatedfrom the components of the shaft 2008 and the end effector 2012 servingas the antenna. For example, the second element 2035 may be positionedin the cartridge 2034, which may be made of a nonelectrically conductivematerial, such as plastic. Because the distal end of the shaft 2008(such as the distal end of the distal closure tube 2042) and theportions of the end effector 2012 serving as the antenna may berelatively close in distance to the second element 2035, the power forthe transmitted signals may be held at low levels, thereby minimizing orreducing interference with other systems in the use environment of theinstrument 2010.

In such an embodiment, the control unit 2300 may be electrically coupledto the shaft 2008 of the instrument 2010, such as to the proximateclosure tube 2040, by an electrically conductive connection 2410 (e.g.,a wire). Portions of the outer shaft 2008, such as the closure tubes2040, 2042, may therefore act as part of an antenna for the control unit2300 by radiating signals in the form of interrogation pulses 2402 tothe second element 2035 and receiving radiated signals in the form ofecho response pulses 2404 from the second element 2035. The echoresponse pulses 2404 received by the control unit 2300 may bedemodulated by the demodulator 2310 and decoded by the decoder 2312 aspreviously discussed. The echo response pulses 2404 may compriseinformation from the second element 2035 such as, the location, type,presence and/or status of various components disposed on the endeffector 2012 portion of the instrument 2010, which the processor 2306may use to control various aspects of the instrument 2010, such as themotor 2065 or a user display.

To transmit data signals to or from the second element 2035 in the endeffector 2012, the electrical connection 2410 may connect the controlunit 2300 to components of the shaft 2008 of the instrument 2010, suchas the proximate closure tube 2040, which may be electrically connectedto the distal closure tube 2042. The distal closure tube 2042 ispreferably electrically insulated from the remote sensor 2368, which maybe positioned in the plastic cartridge 2034. As mentioned before,components of the end effector 2012, such as the channel 2022 and theanvil 2024, may be conductive and in electrical contact with the distalclosure tube 2042 such that they, too, may serve as part of the antenna.

With the shaft 2008 acting as the antenna for the control unit 2300, thecontrol unit 2300 can communicate with the second element 2035 in theend effector 2012 without a direct wired connection. In addition,because the distances between shaft 2008 and the second element 2035 isfixed and known, the power levels could be optimized for low levels tothereby minimize interference with other systems in the use environmentof the instrument 2010.

Although throughout this description, the second element 2035 is showndisposed in the articulating end effector 2012, the second element 2035may be disposed in any suitable location on the instruments 2010 whilemaintaining wireless communication with the first element 2021 (and/orthe shaft 2008) at least on one portion of the transmission or receptioncycle. The second element 2035 also may be coupled to any componentwithin the staple cartridge 2034.

The control unit 2300 may communicate with any of the first 2021, second2035, third 2328 and fourth 2330 elements and additional elementsthrough complex mechanical joints like the rotating joint 2029 without adirect wired connection, but rather through a wireless connection whereit may be difficult to maintain a wired connection. In addition, becausethe distances between the first, second, third, fourth 2021, 2035, 2328,2330 elements, and any additional elements and/or any combinationthereof, may be fixed and known the couplings between these elements2021, 2035, 2328, 2330 may be optimized for efficient inductive transferof electromagnetic energy. Also, these distances may be relatively shortso that relatively low power signals may be used and minimizeinterference with other systems in the use environment of the instrument2010.

In other embodiments, more or fewer sensor elements may be inductively,electromagnetically and/or otherwise coupled. For example, in someembodiments, the control unit 2300 may comprise the first element 2021formed integrally therewith. The first element 2021 in the handle 2006and the second element 2035 in the end effector 2012 can communicatedirectly without the third and fourth elements 2328, 2330. Of course, insuch an embodiment, a stronger signal may be required due to the greaterdistance between the control unit 2300 in the handle 2006 and the secondelement 2035 in the end effector 2012.

In the embodiments described above, the battery 2064 (FIG. 29) powers(at least partially) the firing operation of the instrument 2010. Assuch, the instrument 2010 may be a so-called “power-assist” device. Moredetails and additional embodiments of power-assist devices are describedin the '573 application, which is incorporated herein by reference. Itshould be recognized, however, that the instrument 2010 need not be apower-assist device and that this is merely an example of a type ofdevice that may utilize aspects of the present invention. For example,the instrument 2010 may include a user display (such as a LCD or LEDdisplay) that is powered by the battery 2064 and controlled by thecontrol unit 2300. Data from the sensor transponders 2368 in the endeffector 2012 may be displayed on such a display.

FIGS. 38 and 39 depict a surgical cutting and fastening instrument 3010according to various embodiments of the present invention. Theillustrated embodiment is an endoscopic instrument and, in general, theembodiments of the instrument 3010 described herein are endoscopicsurgical cutting and fastening instruments. It should be noted, however,that according to other embodiments of the present invention, theinstrument may be a non-endoscopic surgical cutting and fasteninginstrument, such as a laparoscopic instrument.

The surgical instrument 3010 depicted in FIGS. 38 and 39 comprises ahandle 3012, a shaft 3014, and an articulating end effector 3016pivotally connected to the shaft 3014 at an articulation pivot 3018.Correct placement and orientation of the end effector 3016 may befacilitated by controls on the handle 3012, including (1) a rotationknob 3017 for rotating the closure tube (described in more detail belowin connection with FIGS. 41-42) at a free rotating joint 3019 of theshaft 3014 to thereby rotate the end effector 3016 and (2) anarticulation control 3020 to effect rotational articulation of the endeffector 3016 about the articulation pivot 3018. In the illustratedembodiment, the end effector 3016 is configured to act as an endocutterfor clamping, severing and stapling tissue, although, in otherembodiments, different types of end effectors may be used, such as endeffectors for other types of surgical devices, such as graspers,cutters, staplers, clip appliers, access devices, drug/gene therapydevices, ultrasound, RF or laser devices, etc.

The handle 3012 of the instrument 3010 may include a closure trigger3022 and a firing trigger 3024 for actuating the end effector 3016. Itwill be appreciated that instruments having end effectors directed todifferent surgical tasks may have different numbers or types of triggersor other suitable controls for operating the end effector 3016. The endeffector 3016 is shown separated from the handle 3012 by a preferablyelongate shaft 3014. In one embodiment, a clinician or operator of theinstrument 3010 may articulate the end effector 3016 relative to theshaft 3014 by utilizing the articulation control 3020 as described inmore detail in U.S. patent application Ser. No. 11/329,020 entitledSURGICAL INSTRUMENT HAVING AN ARTICULATING END EFFECTOR, now U.S. Pat.No. 7,670,334, which is incorporated herein by reference.

The end effector 3016 includes in this example, among other things, astaple channel 3026 and a pivotally translatable clamping member, suchas an anvil 3028, which are maintained at a spacing that assureseffective stapling and severing of tissue clamped in the end effector3016. The handle 3012 includes a pistol grip 3030 towards which aclosure trigger 3022 is pivotally drawn by the clinician to causeclamping or closing of the anvil 3028 toward the staple channel 3026 ofthe end effector 3016 to thereby clamp tissue positioned between theanvil 3028 and the channel 3026. The firing trigger 3024 is fartheroutboard of the closure trigger 3022. Once the closure trigger 3022 islocked in the closure position as further described below, the firingtrigger 3024 may rotate slightly toward the pistol grip 3030 so that itcan be reached by the operator using one hand. The operator may thenpivotally draw the firing trigger 3024 toward the pistol grip 3030 tocause the stapling and severing of clamped tissue in the end effector3016. In other embodiments, different types of clamping members besidesthe anvil 3028 may be used, such as, for example, an opposing jaw, etc.

It will be appreciated that the terms “proximal” and “distal” are usedherein with reference to a clinician gripping the handle 3012 of aninstrument 3010. Thus, the end effector 3016 is distal with respect tothe more proximal handle 3012. It will be further appreciated that, forconvenience and clarity, spatial terms such as “vertical” and“horizontal” are used herein with respect to the drawings. However,surgical instruments are used in many orientations and positions, andthese terms are not intended to be limiting and absolute.

The closure trigger 3022 may be actuated first. Once the clinician issatisfied with the positioning of the end effector 3016, the clinicianmay draw back the closure trigger 3022 to its fully closed, lockedposition proximate to the pistol grip 3030. The firing trigger 3024 maythen be actuated. The firing trigger 3024 returns to the open position(shown in FIGS. 38 and 39) when the clinician removes pressure, asdescribed more fully below. A release button 3032 on the handle 3012,when depressed, may release the locked closure trigger 3022. Variousconfigurations for locking and unlocking the closure trigger 3022 usingthe release button 3032 are described in U.S. patent application Ser.No. 11/343,573, entitled MOTOR-DRIVEN SURGICAL CUTTING AND FASTENINGINSTRUMENT WITH LOADING FORCE FEEDBACK, now U.S. Pat. No. 7,416,101,which is incorporated herein by reference.

FIG. 40A is an exploded view of the end effector 3016 according tovarious embodiments, and FIG. 40B is a perspective view of the cuttinginstrument of FIG. 40A. As shown in the illustrated embodiment, the endeffector 3016 may include, in addition to the previously-mentionedchannel 3026 and anvil 3028, a cutting instrument 3034, a staplecartridge 3038 that is removably seated (e.g., installed) in the channel3026, a sled 3036 disposed within the staple cartridge 3038, and ahelical screw shaft 3040.

The anvil 3028 may be pivotably opened and closed at a pivot point 3042connected to the proximate end of the channel 3026. The anvil 3028 mayalso include a tab 3044 at its proximate end that is inserted into acomponent of the mechanical closure system (described further below) toopen and close the anvil 3028. When the closure trigger 3022 isactuated, that is, drawn in by an operator of the instrument 3010, theanvil 3028 may pivot about the pivot point 3042 into the clamped orclosed position. If clamping of the end effector 3016 is satisfactory,the operator may actuate the firing trigger 3024, which, as explained inmore detail below, causes the cutting instrument 3034 to travellongitudinally along the channel 3026.

As shown, the cutting instrument 3034 includes upper guide pins 3046that enter an anvil slot 3048 in the anvil 3028 to verify and assist inmaintaining the anvil 3028 in a closed state during staple formation andsevering. Spacing between the channel 3026 and anvil 3028 is furthermaintained by the cutting instrument 3034 by having middle pins 3050slide along the top surface of the channel 3026 while a bottom foot 3052opposingly slides along the undersurface of the channel 3026, guided bya longitudinal opening 3054 in the channel 3026. A distally presentedcutting surface 3056 between the upper guide pins 3046 and middle pins3050 severs clamped tissue while distally-presented surface 3058actuates the staple cartridge 3038 by engaging and progressively drivingthe sled 3036 through the staple cartridge 3038 from an unfired positionlocated at a proximal end of the staple cartridge 3038 to a firedposition located at a distal end of the staple cartridge 3038. When thesled 3036 is in the unfired position, the staple cartridge 3038 is in anunfired, or unspent, state. When the sled 3036 is in the fired position,the staple cartridge 3038 is in a fired, or spent, state. Actuation ofthe staple cartridge 3038 causes staple drivers 3060 to cam upwardly,driving staples 3062 out of upwardly open staple holes 3064 formed inthe staple cartridge 3038. The staples 3062 are subsequently formedagainst a staple forming undersurface 66 of the anvil 3028. A staplecartridge tray 3068 encompasses from the bottom the other components ofthe staple cartridge 3038 to hold them in place. The staple cartridgetray 3068 includes a rearwardly open slot 3070 that overlies thelongitudinal opening 3054 in the channel 3026. A lower surface of thestaple cartridge 3038 and an upward surface of the channel 3026 form afiring drive slot 3200 (FIG. 43) through which the middle pins 3050 passduring distal and proximal movement of the cutting instrument 3034. Thesled 3036 may be an integral component of the staple cartridge 3038 suchthat when the cutting instrument 3034 retracts following the cuttingoperation, the sled 3036 does not retract. U.S. Pat. No. 6,978,921,entitled SURGICAL STAPLING INSTRUMENT INCORPORATING AN E-BEAM FIRINGMECHANISM, which is incorporated herein by reference, provides moredetails about such two-stroke cutting and fastening instruments.

It should be noted that although the embodiments of the instrument 3010described herein employ an end effector 3016 that staples the severedtissue, in other embodiments different techniques for fastening orsealing the severed tissue may be used. For example, end effectors thatuse RF energy or adhesives to fasten the severed tissue may also beused. U.S. Pat. No. 5,709,680, entitled ELECTROSURGICAL HEMOSTATICDEVICE, and U.S. Pat. No. 5,688,270, entitled ELECTROSURGICAL HEMOSTATICDEVICE WITH RECESSED AND/OR OFFSET ELECTRODES, both of which areincorporated herein by reference, disclose cutting instruments that useRF energy to fasten the severed tissue. U.S. patent application Ser. No.11/267,811, entitled SURGICAL STAPLING INSTRUMENTS STRUCTURED FORDELIVERY OF MEDICAL AGENTS, now U.S. Pat. No. 7,673,783, and U.S. patentapplication Ser. No. 11/267,383, entitled SURGICAL STAPLING INSTRUMENTSSTRUCTURED FOR PUMP-ASSISTED DELIVERY OF MEDICAL AGENTS, now U.S. Pat.No. 7,607,557, both of which are also incorporated herein by reference,disclose cutting instruments that use adhesives to fasten the severedtissue. Accordingly, although the description herein refers tocutting/stapling operations and the like, it should be recognized thatthis is an exemplary embodiment and is not meant to be limiting. Othertissue-fastening techniques may also be used.

FIGS. 41 and 42 are exploded views and FIG. 43 is a side view of the endeffector 3016 and shaft 3014 according to various embodiments. As shownin the illustrated embodiment, the shaft 3014 may include a proximateclosure tube 3072 and a distal closure tube 3074 pivotably linked by apivot links 3076. The distal closure tube 3074 includes an opening 3078into which the tab 3044 on the anvil 3028 is inserted in order to openand close the anvil 3028, as further described below. Disposed insidethe closure tubes 3072, 3074 may be a proximate spine tube 3079.Disposed inside the proximate spine tube 3079 may be a main rotational(or proximate) drive shaft 3080 that communicates with a secondary (ordistal) drive shaft 3082 via a bevel gear assembly 3084. The secondarydrive shaft 3082 is connected to a drive gear 3086 that engages aproximate drive gear 3088 of the helical screw shaft 3040. The verticalbevel gear 3084 b may sit and pivot in an opening 3090 in the distal endof the proximate spine tube 3079. A distal spine tube 3092 may be usedto enclose the secondary drive shaft 3082 and the drive gears 3086,3088. Collectively, the main drive shaft 3080, the secondary drive shaft3082, and the articulation assembly (e.g., the bevel gear assembly 3084a-c) are sometimes referred to herein as the “main drive shaftassembly.”

A bearing 3094, positioned at a distal end of the staple channel 3026,receives the helical drive screw 3040, allowing the helical drive screw3040 to freely rotate with respect to the channel 3026. The helicalscrew shaft 3040 may interface a threaded opening (not shown) of thecutting instrument 3034 such that rotation of the shaft 3040 causes thecutting instrument 3034 to translate distally or proximately (dependingon the direction of the rotation) through the staple channel 3026.Accordingly, when the main drive shaft 3080 is caused to rotate byactuation of the firing trigger 3024 (as explained in further detailbelow), the bevel gear assembly 3084 a-c causes the secondary driveshaft 3082 to rotate, which in turn, because of the engagement of thedrive gears 3086, 3088, causes the helical screw shaft 3040 to rotate,which causes the cutting instrument 3034 to travel longitudinally alongthe channel 3026 to cut any tissue clamped within the end effector 3016.The sled 3036 may be made of, for example, plastic, and may have asloped distal surface. As the sled 3036 traverses the channel 3026, thesloped distal surface may cam the staple drivers 3060 upward, which inturn push up or drive the staples 3062 in the staple cartridge 3038through the clamped tissue and against the staple forming undersurface3066 of the anvil 3028, thereby stapling the severed tissue. When thecutting instrument 3034 is retracted, the cutting instrument 3034 andthe sled 3036 may become disengaged, thereby leaving the sled 3036 atthe distal end of the channel 3026.

FIGS. 44-47 illustrate an exemplary embodiment of a motor-drivenendocutter, and in particular the handle 3012 thereof, that providesoperator-feedback regarding the deployment and loading force of thecutting instrument 3034 in the end effector 3016. In addition, theembodiment may use power provided by the operator in retracting thefiring trigger 3024 to power the device (a so-called “power assist”mode). As shown in the illustrated embodiment, the handle 3012 includesexterior lower side pieces 3096, 3098 and exterior upper side pieces3100, 3102 that fit together to form, in general, the exterior of thehandle 3012. A battery 3104 may be provided in the pistol grip portion3030 of the handle 3012. The battery 3104 may be constructed accordingto any suitable construction or chemistry including, for example, aLi-ion chemistry such as LiCoO₂ or LiNiO₂, a Nickel Metal Hydridechemistry, etc. The battery 3104 powers a motor 3106 disposed in anupper portion of the pistol grip portion 3030 of the handle 3012.According to various embodiments, the motor 3106 may be a DC brusheddriving motor having a maximum rotation of approximately 5000 to 100,000RPM. The motor 3106 may drive a 90-degree bevel gear assembly 3108comprising a first bevel gear 3110 and a second bevel gear 3112. Thebevel gear assembly 3108 may drive a planetary gear assembly 3114. Theplanetary gear assembly 3114 may include a pinion gear 3116 connected toa drive shaft 3118. The pinion gear 3116 may drive a mating ring gear3120 that drives a helical gear drum 3122 via a drive shaft 3124. A ring3126 may be threaded on the helical gear drum 3122. Thus, when the motor3106 rotates, the ring 3126 is caused to travel along the helical geardrum 3122 by means of the interposed bevel gear assembly 3108, planetarygear assembly 3114 and ring gear 3120.

The handle 3012 may also include a run motor sensor 3128 incommunication with the firing trigger 3024 to detect when the firingtrigger 3024 has been drawn in (or “closed”) toward the pistol gripportion 3030 of the handle 3012 by the operator to thereby actuate thecutting/stapling operation by the end effector 3016. The sensor 3128 maybe a proportional sensor such as, for example, a rheostat or variableresistor. When the firing trigger 3024 is drawn in, the sensor 3128detects the movement, and sends an electrical signal indicative of thevoltage (or power) to be supplied to the motor 3106. When the sensor3128 is a variable resistor or the like, the rotation of the motor 3106may be generally proportional to the amount of movement of the firingtrigger 3024. That is, if the operator only draws or closes the firingtrigger 3024 in a little bit, the rotation of the motor 3106 isrelatively low. When the firing trigger 3024 is fully drawn in (or inthe fully closed position), the rotation of the motor 3106 is at itsmaximum. In other words, the harder the operator pulls on the firingtrigger 3024, the more voltage is applied to the motor 3106, causing agreater rate of rotation. In another embodiment, for example, thecontrol unit (described further below) may output a PWM control signalto the motor 3106 based on the input from the sensor 3128 in order tocontrol the motor 3106.

The handle 3012 may include a middle handle piece 3130 adjacent to theupper portion of the firing trigger 3024. The handle 3012 also maycomprise a bias spring 3132 connected between posts on the middle handlepiece 3130 and the firing trigger 3024. The bias spring 3132 may biasthe firing trigger 3024 to its fully open position. In that way, whenthe operator releases the firing trigger 3024, the bias spring 3132 willpull the firing trigger 3024 to its open position, thereby removingactuation of the sensor 3128, thereby stopping rotation of the motor3106. Moreover, by virtue of the bias spring 3132, any time an operatorcloses the firing trigger 3024, the operator will experience resistanceto the closing operation, thereby providing the operator with feedbackas to the amount of rotation exerted by the motor 3106. Further, theoperator could stop retracting the firing trigger 3024 to thereby removeforce from the sensor 3128, to thereby stop the motor 3106. As such, theoperator may stop the deployment of the end effector 3016, therebyproviding a measure of control of the cutting/fastening operation to theoperator.

The distal end of the helical gear drum 3122 includes a distal driveshaft 3134 that drives a ring gear 3136, which mates with a pinion gear3138. The pinion gear 3138 is connected to the main drive shaft 3080 ofthe main drive shaft assembly. In that way, rotation of the motor 3106causes the main drive shaft assembly to rotate, which causes actuationof the end effector 3016, as described above.

The ring 3126 threaded on the helical gear drum 3122 may include a post3140 that is disposed within a slot 3142 of a slotted arm 3144. Theslotted arm 3144 has an opening 3146 its opposite end 3148 that receivesa pivot pin 3150 that is connected between the handle exterior sidepieces 3096, 3098. The pivot pin 3150 is also disposed through anopening 3152 in the firing trigger 3024 and an opening 3154 in themiddle handle piece 3130.

In addition, the handle 3012 may include a reverse motor (orend-of-stroke) sensor 3156 and a stop motor (or beginning-of-stroke)sensor 3158. In various embodiments, the reverse motor sensor 3156 maybe a normally-open limit switch located at the distal end of the helicalgear drum 3122 such that the ring 3126 threaded on the helical gear drum3122 contacts and closes the reverse motor sensor 3156 when the ring3126 reaches the distal end of the helical gear drum 3122. The reversemotor sensor 3156, when closed, sends a signal to the control unit whichsends a signal to the motor 3106 to reverse its rotation direction,thereby withdrawing the cutting instrument of the end effector 3016following the cutting operation.

The stop motor sensor 3158 may be, for example, a normally-closed limitswitch. In various embodiments, it may be located at the proximate endof the helical gear drum 3122 so that the ring 3126 opens the switch3158 when the ring 3126 reaches the proximate end of the helical geardrum 3122.

In operation, when an operator of the instrument 3010 pulls back thefiring trigger 3024, the sensor 3128 detects the deployment of thefiring trigger 3024 and sends a signal to the control unit which sends asignal to the motor 3106 to cause forward rotation of the motor 3106 at,for example, a rate proportional to how hard the operator pulls back thefiring trigger 3024. The forward rotation of the motor 3106 in turncauses the ring gear 3120 at the distal end of the planetary gearassembly 3114 to rotate, thereby causing the helical gear drum 3122 torotate, causing the ring 3126 threaded on the helical gear drum 3122 totravel distally along the helical gear drum 3122. The rotation of thehelical gear drum 3122 also drives the main drive shaft assembly asdescribed above, which in turn causes deployment of the cuttinginstrument 3034 in the end effector 3016. That is, the cuttinginstrument 3034 and sled 3036 are caused to traverse the channel 3026longitudinally, thereby cutting tissue clamped in the end effector 3016.Also, the stapling operation of the end effector 3016 is caused tohappen in embodiments where a stapling-type end effector is used.

By the time the cutting/stapling operation of the end effector 3016 iscomplete, the ring 3126 on the helical gear drum 3122 will have reachedthe distal end of the helical gear drum 3122, thereby causing thereverse motor sensor 3156 to be actuated, which sends a signal to thecontrol unit which sends a signal to the motor 3106 to cause the motor3106 to reverse its rotation. This in turn causes the cutting instrument3034 to retract, and also causes the ring 3126 on the helical gear drum3122 to move back to the proximate end of the helical gear drum 3122.

The middle handle piece 3130 includes a backside shoulder 3160 thatengages the slotted arm 3144 as best shown in FIGS. 45 and 46. Themiddle handle piece 3130 also has a forward motion stop 3162 thatengages the firing trigger 3024. The movement of the slotted arm 3144 iscontrolled, as explained above, by rotation of the motor 3106. When theslotted arm 3144 rotates CCW as the ring 3126 travels from the proximateend of the helical gear drum 3122 to the distal end, the middle handlepiece 3130 will be free to rotate CCW. Thus, as the operator draws inthe firing trigger 3024, the firing trigger 3024 will engage the forwardmotion stop 3162 of the middle handle piece 3130, causing the middlehandle piece 3130 to rotate CCW. Due to the backside shoulder 3160engaging the slotted arm 3144, however, the middle handle piece 3130will only be able to rotate CCW as far as the slotted arm 3144 permits.In that way, if the motor 3106 should stop rotating for some reason, theslotted arm 3144 will stop rotating, and the operator will not be ableto further draw in the firing trigger 3024 because the middle handlepiece 3130 will not be free to rotate CCW due to the slotted arm 3144.

FIGS. 48 and 49 illustrate two states of a variable sensor that may beused as the run motor sensor 3128 according to various embodiments ofthe present invention. The sensor 3128 may include a face portion 3164,a first electrode (A) 3166, a second electrode (B) 3168, and acompressible dielectric material 3170 (e.g., EAP) between the electrodes3166, 3168. The sensor 3128 may be positioned such that the face portion3164 contacts the firing trigger 3024 when retracted. Accordingly, whenthe firing trigger 3024 is retracted, the dielectric material 3170 iscompressed, as shown in FIG. 49, such that the electrodes 3166, 3168 arecloser together. Since the distance “b” between the electrodes 3166,3168 is directly related to the impedance between the electrodes 3166,3168, the greater the distance the more impedance, and the closer thedistance the less impedance. In that way, the amount that the dielectricmaterial 3170 is compressed due to retraction of the firing trigger 3024(denoted as force “F” in FIG. 49) is proportional to the impedancebetween the electrodes 3166, 3168. This impedance provided by the sensor3128 may be used with suitable signal conditioning circuitry toproportionally control the speed of the motor 3106, for example.

Components of an exemplary closure system for closing (or clamping) theanvil 3028 of the end effector 3016 by retracting the closure trigger3022 are also shown in FIGS. 44-47. In the illustrated embodiment, theclosure system includes a yoke 3172 connected to the closure trigger3022 by a pin 3174 that is inserted through aligned openings in both theclosure trigger 3022 and the yoke 3172. A pivot pin 3176, about whichthe closure trigger 3022 pivots, is inserted through another opening inthe closure trigger 3022 which is offset from where the pin 3174 isinserted through the closure trigger 3022. Thus, retraction of theclosure trigger 3022 causes the upper part of the closure trigger 3022,to which the yoke 3172 is attached via the pin 3174, to rotate CCW. Thedistal end of the yoke 3172 is connected, via a pin 3178, to a firstclosure bracket 3180. The first closure bracket 3180 connects to asecond closure bracket 3182. Collectively, the closure brackets 3180,3182 define an opening in which the proximal end of the proximateclosure tube 3072 (see FIG. 41) is seated and held such thatlongitudinal movement of the closure brackets 3180, 3182 causeslongitudinal motion by the proximate closure tube 3072. The instrument3010 also includes a closure rod 3184 disposed inside the proximateclosure tube 3072. The closure rod 3184 may include a window 3186 intowhich a post 3188 on one of the handle exterior pieces, such as exteriorlower side piece 3096 in the illustrated embodiment, is disposed tofixedly connect the closure rod 3184 to the handle 3012. In that way,the proximate closure tube 3072 is capable of moving longitudinallyrelative to the closure rod 3184. The closure rod 3184 may also includea distal collar 3190 that fits into a cavity 3192 in proximate spinetube 3079 and is retained therein by a cap 3194 (see FIG. 41).

In operation, when the yoke 3172 rotates due to retraction of theclosure trigger 3022, the closure brackets 3180, 3182 cause theproximate closure tube 3072 to move distally (i.e., away from the handle3012 of the instrument 3010), which causes the distal closure tube 3074to move distally, which causes the anvil 3028 to rotate about the pivotpoint 3042 into the clamped or closed position. When the closure trigger3022 is unlocked from the locked position, the proximate closure tube3072 is caused to slide proximally, which causes the distal closure tube3074 to slide proximally, which, by virtue of the tab 3044 beinginserted in the opening 3078 of the distal closure tube 3074, causes theanvil 3028 to pivot about the pivot point 3042 into the open orunclamped position. In that way, by retracting and locking the closuretrigger 3022, an operator may clamp tissue between the anvil 3028 andchannel 3026, and may unclamp the tissue following the cutting/staplingoperation by unlocking the closure trigger 3022 from the lockedposition.

The control unit (described further below) may receive the outputs fromend-of-stroke and beginning-of-stroke sensors 3156, 3158 and therun-motor sensor 3128, and may control the motor 3106 based on theinputs. For example, when an operator initially pulls the firing trigger3024 after locking the closure trigger 3022, the run-motor sensor 3128is actuated. If the control unit determines that an unspent staplecartridge 3038 is present in the end effector 3016, as described furtherbelow, the control unit may output a control signal to the motor 3106 tocause the motor 3106 to rotate in the forward direction. When the endeffector 3016 reaches the end of its stroke, the reverse motor sensor3156 will be activated. The control unit may receive this output fromthe reverse motor sensor 3156 and cause the motor 3106 to reverse itsrotational direction. When the cutting instrument 3034 is fullyretracted, the stop motor sensor switch 3158 is activated, causing thecontrol unit to stop the motor 3106.

According to various embodiments, the instrument 3010 may include atransponder in the end effector 3016. The transponder may generally beany device suitable for transmitting a wireless signal(s) indicating oneor more conditions of the end effector 3016. In certain embodiments, forexample, wireless signals may be transmitted by the transponder to thecontrol unit responsive to wireless signals received from the controlunit. In such embodiments, the wireless signals transmitted by thecontrol unit and the transponder are referred to as “interrogation” and“reply” signals, respectively. The transponder may be in communicationwith one or more types of sensors (e.g., position sensors, displacementsensors, pressure/load sensors, proximity sensors, etc.) located in theend effector 3016 for transducing various end effector conditions suchas, for example, a state of the staple cartridge 3038 (e.g., fired orunfired) and the respective positions of the anvil 3028 (e.g., open orclosed) and the sled 3036 (e.g., proximal or distal). According tovarious embodiments and as discussed below, the transponder may be apassive device such that its operating power is derived from wirelesssignals (e.g., interrogation signals). In other embodiments, thetransponder may be an active device powered by a self-contained powersource (e.g., a battery) disposed within the end effector 3016. Thetransponder and the control circuit may be configured to communicateusing any suitable type of wireless signal. According to variousembodiments and as discussed below, for example, the transponder and thecontrol circuit may transmit and receive wireless signals using magneticfields generated by inductive effects. It will be appreciated that thetransponder and the control circuit may instead transmit and receivewireless signals using electromagnetic fields (e.g., RF signals, opticalsignals), or using electric fields generated by capacitive effects, forexample. It will further be appreciated that the end effector 3016 mayinclude additional transponders, with each transponder having one morededicated sensors for inputting data thereto.

FIG. 50 illustrates a block diagram of the control unit 3196 accordingto various embodiments. As shown, the control unit 3196 may comprise aprocessor 3198 and one or more memory units 3200. The control unit 3196may be powered by the battery 3104 or other suitable power sourcecontained within the instrument 3010. In certain embodiments, thecontrol unit 3196 may further comprise an inductive element 3202 (e.g.,a coil or antenna) to transmit and receive wireless signals (e.g.,interrogation and reply signals) from the transponder via magneticfields. Signals received by the inductive element 3202 may bedemodulated by a demodulator 3204 and decoded by a decoder 3206. Byexecuting instruction code stored in the memory 3200, the processor 3198may control various components of the instrument 3010, such as the motor3106 and a user display (not shown), based on inputs of the end effectorsensors (as indicated by the decoded signals) and inputs received fromother various sensor(s) (such as the run-motor sensor 3128, theend-of-stroke and beginning-of-stroke sensors 3156, 3158, for example).

Wireless signals output by the control unit 3196 may be in the form ofalternating magnetic fields emitted by the inductive element 3202. Thecontrol unit 3196 may comprise an encoder 3208 for encoding data to betransmitted to the transponder and a modulator 3210 for modulating themagnetic field based on the encoded data using a suitable modulationscheme. The control unit 3196 may communicate with the transponder usingany suitable wireless communication protocol and any suitable frequency(e.g., an ISM band or other RF band). Also, the control unit 3196 maytransmit signals at a different frequency range than the frequency rangeof the reply signals received from the transponder. Additionally,although only one antenna (inductive element 3202) is shown in FIG. 50,in other embodiments the control unit 3196 may have separate receivingand transmitting antennas.

According to various embodiments, the control unit 3196 may comprise amicrocontroller, a microprocessor, a field programmable gate array(FPGA), one or more other types of integrated circuits (e.g., RFreceivers and PWM controllers), and/or discrete passive components. Thecontrol unit 3196 may also be embodied as system-on-chip (SoC) or asystem-in-package (SIP), for example.

As shown in FIG. 51, the control unit 3196 may be housed in the handle3012 of the instrument 3010 and the transponder 3212 may be located inthe end effector 3016. To transmit signals to the transponder 3212 andreceive signals therefrom, the inductive element 3202 of the controlunit 3196 may be inductively coupled to a secondary inductive element(e.g., a coil) 3214 positioned in the shaft 3014 distally from therotation joint 3019. The secondary inductive element 3214 is preferablyelectrically insulated from the conductive shaft 3014.

The secondary inductive element 3214 may be connected by an electricallyconductive, insulated wire 3216 to a distal inductive element (e.g., acoil) 3218 located near the end effector 3016, and preferably distallylocated relative to the articulation pivot 3018. The wire 3216 may bemade of an electrically conductive polymer and/or metal (e.g., copper)and may be sufficiently flexible so that it could pass though thearticulation pivot 3018 and not be damaged by articulation. The distalinductive element 3218 may be inductively coupled to the transponder3212 in, for example, the staple cartridge 3038 of the end effector3016. The transponder 3212, as described in more detail below, mayinclude an antenna (or coil) for inductively coupling to the distal coil3218, as well as associated circuitry for transmitting and receivingwireless signals.

In certain embodiments, the transponder 3212 may be passively powered bymagnetic fields emitted by the distal inductive element 3218. Oncesufficiently powered, the transponder 3212 may transmit and/or receivedata (e.g., by modulating the magnetic fields) to the control unit 3196in the handle 3012 via (i) the inductive coupling between thetransponder 3212 and the distal inductive element 3218, (ii) the wire3216, and (iii) the inductive coupling between the secondary inductiveelement 3214 and the control unit 3196. The control unit 3196 may thuscommunicate with the transponder 3212 in the end effector 3016 without ahardwired connection through complex mechanical joints like the rotatingjoint 3019 and/or without a hardwired connection from the shaft 3014 tothe end effector 3016, places where it may be difficult to maintain suchconnections. In addition, because the distances between the inductiveelements (e.g., the spacing between (i) the transponder 3212 and thedistal inductive element 3218, and (ii) the secondary inductive element3214 and the control unit 3196) are fixed and known, the couplings couldbe optimized for inductive energy transfer. Also, the distances could berelatively short so that relatively low power signals could be used tothereby minimize interference with other systems in the use environmentof the instrument 3010.

In the embodiment of FIG. 51, the inductive element 3202 of the controlunit 3196 is located relatively near to the control unit 3196. Accordingto other embodiments, as shown in FIG. 52, the inductive element 3202 ofthe control unit 3196 may be positioned closer to the rotating joint3019 to that it is closer to the secondary inductive element 3214,thereby reducing the distance of the inductive coupling in such anembodiment. Alternatively, the control unit 3196 (and hence theinductive element 3202) could be positioned closer to the secondaryinductive element 3214 to reduce the spacing.

In other embodiments, more or fewer than two inductive couplings may beused. For example, in some embodiments, the surgical instrument 3010 mayuse a single inductive coupling between the control unit 3196 in thehandle 3012 and the transponder 3212 in the end effector 3016, therebyeliminating the inductive elements 3214, 3218 and the wire 3216. Ofcourse, in such an embodiment, stronger signals may be required due tothe greater distance between the control unit 3196 in the handle 3012and the transponder 3212 in the end effector 3016. Also, more than twoinductive couplings could be used. For example, if the surgicalinstrument 3010 had numerous complex mechanical joints where it would bedifficult to maintain a hardwired connection, inductive couplings couldbe used to span each such joint. For example, inductive couplings couldbe used on both sides of the rotary joint 3019 and both sides of thearticulation pivot 3018, with an inductive element 3220 on the distalside of the rotary joint 3019 connected by the wire 3216 to theinductive element 3218 of the proximate side of the articulation pivot,and a wire 3222 connecting inductive elements 3224, 3226 on the distalside of the articulation pivot 3018 as shown in FIG. 53. In thisembodiment, the inductive element 3226 may communicate with thetransponder 3212.

In the above-described embodiments, each of the inductive elements 3202,3214, 3218, 3224, 3226 may or may not include ferrite cores.Additionally, the inductive elements 3214, 3218, 3224, 3226 are alsopreferably insulated from the electrically conductive outer shaft (orframe) of the instrument 3010 (e.g., the closure tubes 3072, 3074), andthe wires 3216, 3222 are also preferably insulated from the outer shaft3014.

FIG. 54 is a bottom view of a portion of the staple cartridge 3038including the transponder 3212 according to various embodiments. Asshown, the transponder 3212 may be held or embedded in the staplecartridge 3038 at its distal end using a suitable bonding material, suchas epoxy.

FIG. 55 illustrates a circuit diagram of the transponder 3212 accordingto various embodiments. As shown, the transponder 3212 may include aresonant circuit 3249 comprising an inductive element 3250 (e.g., a coilor antenna) and a capacitor 3252. The transponder 3212 may furtherinclude a microchip 3254 coupled to the resonant circuit 3249. Incertain embodiments, the microchip 3254 may be, for example, an RFIDdevice containing circuitry for enabling communication with the controlunit 3196 via the inductive element 3250 of the resonant circuit 3249.The microchip 3254 may include at least one data input for receivingdata in the form of discrete or analog signals from the sensors 3235disposed in the end effector 3016. As discussed above, the sensors 3235may include, for example, position sensors, displacement sensors,pressure/load sensors, proximity sensors for sensing various endeffector conditions. The microchip 3254 also may include one or moredynamic memory devices 3255 (e.g., flash memory devices) for storingdata transmitted from, for example, the control unit 3196. The microchip3254 may further include one or more non-dynamic memory devices 3257(e.g., write-once memory devices) for storing static data, such as, forexample, a staple cartridge identification number, manufacturerinformation, and information pertaining to physical characteristics ofthe staple cartridge 3038.

In response to alternating magnetic fields emitted by the distalinductive element 3218, the resonant circuit 3249 of the transponder3212 is caused to resonate, thereby causing an alternating input voltageto be applied to the microchip 3254. The resonant circuit 3249 may havea resonant frequency given by

${f_{r} = \frac{1}{2\pi\sqrt{L_{1}C_{1}}}},$where L₁ is the inductance value of the inductive element 3250 and C₁ isthe capacitance value of the capacitor 3252. The values of L₁ and C₁ maybe selected such that the resonant frequency of the circuit 3249 isequal or nearly equal to the frequency of magnetic field transmitted bythe distal inductive element 3218. The circuitry of the microchip 3254may include a rectifying circuitry (not shown) for rectifying andconditioning the alternating input voltage to provide a DC voltagesufficient to power the microchip 3254. Once powered, the microchip 3254may selectively load the inductive element 3250 based on data receivedfrom the sensors 3235 and the data stored in the memory devices 3255,3257, thus modulating the magnetic fields coupling the distal inductiveelement 3218 and the inductive element 3250. The modulation of themagnetic field modulates the voltage across the distal inductive element3218, which in turn modulates the voltage across the inductive element3202 of the control unit 3196. The control unit 3196 may demodulate anddecode the voltage signal across the inductive element 3202 to extractdata communicated by the microchip 3254. The control unit 3196 mayprocess the data to verify, among other things, that the staplecartridge 3038 is compatible with the instrument 3010 and that endeffector conditions are suitable for conducting a firing operation.Subsequent to verification of the data, the control unit 3196 may enablea firing operation.

According to various embodiments, the resonant circuit 3249 may furtherinclude a fuse 3256 connected in series with the inductive element 3250.When the fuse 3256 is closed (e.g., conductive), the inductive element3250 is electrically coupled to the resonant circuit 3249, thus enablingthe transponder 3212 to function as described above in response to analternating magnetic field emitted by the distal inductive element 3218.The closed state of the fuse 3256 thus corresponds to an enabled stateof the transponder 3212. When the fuse 3256 is opened (e.g.,non-conductive), the inductive element 3250 is electrically disconnectedfrom the resonant circuit 3249, thus preventing the resonant circuit3249 from generating the voltage necessary to operate the microchip3254. The open state of the fuse 3256 thus corresponds to a disabledstate of the transponder 3212. The placement of the fuse 3256 in FIG. 55is shown by way of example only, and it will be appreciated that thefuse 3256 may be connected in any manner such that the transponder 3212is disabled when the fuse 3256 is opened.

According to various embodiments, the fuse 3256 may be actuated (e.g.,transitioned from closed to opened) substantially simultaneously with afiring operation of the instrument 3010. For example, the fuse 3256 maybe actuated immediately before, during, or immediately after a firingoperation. Actuation of the fuse 3256 thus transitions the transponder3212 from the enabled state to the disabled state. Accordingly, if anattempt is made to reuse the staple cartridge 3038, the transponder 3212will be unable to communicate data in response to a wireless signaltransmitted by the distal inductive element 3218. Based upon the absenceof this data, the control unit 3196 may determine that the transponder3212 is in a disabled state indicative of the fired state of the staplecartridge 3038 and prevent a firing operation from being enabled. Thus,actuation of the fuse 3256 prevents reuse of a staple cartridge 3038when the staple cartridge 3038 is in the fired state.

In certain embodiments, the fuse 3256 may be a mechanically-actuatedfuse that is opened in response to movement of the cutting instrument3034 when actuated, for example. As shown in FIG. 56, for example, thefuse 3256 may include a section of wire extending transversely across alongitudinal slot 3258 of the staple cartridge 3038 through which thecutting instrument 3034 passes during a firing operation. When theinstrument 3010 is fired, the distal movement of the cutting instrument3034 severs the fuse 3256, thus transitioning the transponder 3212 tothe disabled state so that it cannot be reused.

According to other embodiments, the fuse 3256 may be anelectrically-actuated fuse. For example, subsequent to receiving datafrom the transponder 3212 and verifying that the end effector 3016 is ina condition to be fired, the control unit 3196 may transmit a wirelesssignal to the transponder 3212 such that the resulting current flowthrough fuse 3256 is sufficient to cause the fuse 3256 to open. It willbe appreciated that the strength of the wireless signal needed to openthe fuse 3256 may be different in amplitude, frequency, and durationthan that used to communicate with the transponder 3212. Additionally,it will be appreciated that other electrically-actuated components maybe used instead of an electrically-actuated fuse to disable thetransponder 3212. For example, the control unit 3196 may transmit awireless signal to the transponder 3212 such that resulting voltagedeveloped across the resonant circuit 3256 sufficiently exceeds thevoltage rating of the capacitor 3252 and/or circuitry of the microchip3254 to cause their destruction.

As an alternative to using an electrically-actuated fuse, the fuse 3256may instead be a thermally-actuated fuse (e.g., a thermal cutoff fuse)that is caused to open in response to heat generated by the flow ofexcessive current therethrough.

In certain cases, it may be desirable to communicate with thetransponder 3212 when the staple cartridge 3038 is in the fired state.In such cases, it is not possible to entirely disable the transponder3212 as described in the embodiments above. FIG. 57 illustrates acircuit diagram of the transponder 3212 according to various embodimentsfor enabling wireless communication with the control unit 3196 when thestaple cartridge 3038 is in the fired state. As shown, the resonantcircuit 3249 of the transponder 3212 may include a second capacitor 3260in parallel with the capacitor 3252. The fuse 3256 may be connected inseries with the second capacitor 3260 such that the resonant frequencyof the resonant circuit 3249 is determined by the open/closed state ofthe fuse 3256. In particular, when the fuse 3256 is closed, the resonantfrequency is given by

${f_{r} = \frac{1}{2\pi\sqrt{L_{1}\left( {C_{1} + C_{2}} \right)}}},$where C₂ is the capacitance value of the second capacitor 3260.

The closed state of the fuse 3256 thus corresponds to a first resonantstate of the transponder 3212. When the fuse 3256 is opened, theresonant frequency is given by

$f_{r} = {\frac{1}{2\pi\sqrt{L_{1}C_{1}}}.}$The open state of the fuse 3256 thus corresponds to a second resonantstate of the transponder 3212. As described in the above embodiments,the fuse 3256 may be mechanically, electrically or thermally actuatedsubstantially simultaneously with a firing operation. The control unit3196 may be configured to determine the resonant state of thetransponder 3212 (and thus the unfired/fired state of the staplecartridge 3038) by discriminating between the two resonant frequencies.Advantageously, because the resonant circuit 3256 (and thus themicrochip 3254) continues to operate after the fuse 3256 is opened, thecontrol unit 3196 may continue to receive data from the transponder3212. It will be appreciated that the placement of the fuse 3256 and useof the second capacitor 3260 to alter the resonant frequency is providedby way of example only. In other embodiments, for example, the fuse 3256may be connected such that the inductive value of the inductive element3250 is changed when the fuse 3256 is opened (e.g., by connecting thefuse 3256 such that a portion of the inductive element 3250 isshort-circuited when the fuse 3256 is closed).

According to various embodiments, a switch may be used as an alternativeto the fuse 3256 for effecting the transition between transponderstates. For example, as shown in FIG. 58, the staple cartridge tray 3068of the staple cartridge 3038 may include a switch 3262 (e.g., anormally-open limit switch) located at its proximal end. The switch 3262may be mounted such that when the sled 3036 is present in the unfiredposition, the sled 3036 maintains the switch 3262 in a closed (e.g.,conductive) state. When the sled 3036 is driven from the unfiredposition to the fired position during a firing operation, the switch3262 transitions to an open (e.g., non-conductive state), thus effectinga transition in the state of the transponder 3212 as described above. Itwill be appreciated that in other embodiments the switch 3262 may be anormally-closed switch mounted at the distal end of the staple cartridgetray 3068 such that the switch 3262 is caused to open when the sled 3036is present in the fired position. It will further be appreciated thatthe switch 3262 may be located at the proximal or distal ends of thestaple cartridge 3038 and mounted such that it may be suitably actuatedby the sled 3036 when present in the unfired and fired positions,respectively.

As an alternative to connecting the mechanically-actuated fuse 3256 orthe switch 3262 to disable/alter the resonant circuit 3249, thesecomponents may instead be connected to data inputs of the microchip3254. In this way, the open/closed states of the mechanically-actuatedfuse 3256 or the switch 3262 may be transmitted to the control unit 3196in the same manner as the data corresponding to other end effectorconditions.

As an alternative to the fuse 3256 and the switch 3262, embodiments ofthe present invention may instead utilize alterable data values in adynamic memory device 3255 of the transponder 3212. For example, thedynamic memory device 3255 may store a first data value (e.g., a databit having a value of 1) corresponding to a first data state of thetransponder 3212. The first data value may be written to the dynamicmemory device 3255 during the manufacture of the staple cartridge 3038,for example. The first data state may thus be indicative of the unfiredstate of the staple cartridge 3038. Based on a determination of thefirst data state of the transponder 3212, the control unit 3196 mayenable operation of the instrument 3010 if the end effector conditionsare otherwise suitable for conducting a firing operation. Substantiallysimultaneously with the firing operation, the control unit 3196 maytransmit a wireless signal to the transponder 3212 containing a seconddata value (e.g., a data bit having a value of 0). The second data valuemay be stored to the dynamic memory device 3255 such that the first datavalue is overwritten, thus transitioning the transponder 3212 from thefirst data state to a second data state. The second data state may thusbe indicative of the fired state of the staple cartridge 3038. If anattempt is made to reuse the staple cartridge 3038, the control unit3196 may determine that the transponder 3212 is in the second data stateand prevent a firing operation from being enabled.

Although the transponders 3212 in the above-described embodimentsincludes a microchip 3254 for wirelessly communicating data stored inmemory devices 3235, 3237 and data input from the sensors 3235, in otherembodiments the transponder may not include a microchip 3254. Forexample, FIG. 59 illustrates a “chipless” transponder 3264 in the formof a resonant circuit having components similar to those of the resonantcircuit 3249, such as an inductive element 3250, a capacitor 3252, and afuse 3256. Additionally, the transponder 3264 may include one or moresensors 3235 connected in series with the components 3250, 3252, 3256.In certain embodiments and as shown, each sensor 3235 may be a limitswitch (e.g., a normally open or a normally closed limit switch) mountedin the end effector 3016 for sensing a corresponding end effectorcondition (e.g., a position of the anvil 3028, a position of the sled3036, etc.). In such embodiments, each limit switch 3235 may be in aclosed (e.g., conductive) state when its sensed condition is compatiblewith a firing operation, thus establishing electrical continuity throughthe resonant circuit.

When each switch 3235 and the fuse 3256 is in the closed state, theresonant circuit will be caused to resonate at a frequency f_(r)responsive to a magnetic field emitted by the distal inductive element3218. The closed states of the fuse 3256 and the switches 3235 thuscorrespond to an enabled state of the transponder 3264 that isindicative of, among other things, the unfired state of the staplecartridge 3038. The control unit 3196 may sense the resonance (e.g., bysensing magnetic field loading caused by the resonant circuit) todetermine the enabled state, at which time the control unit 3196 mayenable operation of the instrument 3010. Substantially simultaneouslywith the actuation of the cutting instrument 3034, the fuse 3256 may bemechanically, electronically or thermally actuated as described above,thus transitioning the transponder 3264 to a disabled state indicativeof the fired state of the staple cartridge 3038. If a subsequent firingoperation is attempted without replacing the staple cartridge 3038, thecontrol unit 3196 may determine the disabled state based on the absenceof a sensed resonance in response to an emitted magnetic field, in whichcase the control unit 3196 prevents the firing operation from beingperformed.

FIG. 60 illustrates another embodiment of a chipless transponder 3264 inthe form of a resonant circuit including an inductive element 3250, afirst capacitor 3252, a second capacitor 3260, and a fuse 3256 connectedin series with the second capacitor 3260. The fuse 3256 may bemechanically, electronically or thermally actuated substantiallysimultaneously with a firing operation, as in above-describedembodiments. The transponder 3264 may additionally include one or moresensors 3235 (e.g., limit switches) connected in series with a thirdcapacitor 3266 of the resonant circuit. Accordingly, when each switch3235 and the fuse 3256 are in the closed state, the resonant circuitwill be caused to resonate at a frequency

$f_{r\; 1} = \frac{1}{2\pi\sqrt{L_{1}\left( {C_{1} + C_{2} + C_{3}} \right)}}$responsive to a magnetic field emitted by the distal inductive element3218. When one of the switches 3235 is opened and the fuse 3256 isclosed, the resonant frequency will be

${f_{r\; 2} = \frac{1}{2\pi\sqrt{L_{1}\left( {C_{1} + C_{2}} \right)}}},$and when each of the switches 3235 is closed and the fuse 3256 isopened, the resonant frequency will be

$f_{r\; 3} = {\frac{1}{2\pi\sqrt{L_{1}\left( {C_{1} + C_{3}} \right)}}.}$When the switches 3235 and the fuse 3256 are opened, the resonantfrequency will be

$f_{r\; 4} = {\frac{1}{2\pi\sqrt{L_{1}C_{1}}}.}$The closed states of the fuse 3256 and the switches 3235 correspond to afirst resonant state (e.g., resonant frequency f_(r1)) of thetransponder 3264, and the open state of the fuse 3256 corresponds to asecond resonant state (e.g., either of resonant frequencies f_(r3) orf_(r4)). The capacitance values C₁, C₂ and C₃ may be selected such thatthe resonant frequencies f_(r1), f_(r2), f_(r3) and f_(r4) aredifferent. The control unit 3196 may be configured to discriminatebetween resonant frequencies to determine the first or second state ofthe transponder 3266 (and thus the unfired or fired state of the staplecartridge 3038), and to enable or prevent operation of the instrument3010 accordingly. The control unit 3196 may further be configured todetermine a third state of the transponder 3264 corresponding the closedstate of the fuse 3256 and an open state of any of the switches 3235. Inthis case, the control unit 3196 may operate to prevent a firingoperation until the end effector condition(s) causing the openswitch(es) 3235 is resolved.

FIG. 61 is a flow diagram of a method of preventing reuse of a staplecartridge in surgical instrument that may be performed in conjunctionwith embodiments of the instrument 3010 described above. At step 3300, afirst wireless signal is transmitted to the transponder 3212, 3264 andat step 3305 a second wireless signal is received from the transponder3212, 3264 such that one of a first electronic state and a secondelectronic state of the transponder 3212, 3264 may be determined basedon the second wireless signal. In certain embodiments and as explainedabove, the wireless signals may be magnetic signals generated byinductive effects, although electric fields and electromagnetic fieldsmay alternatively be employed. States of the transponder 3212, 3264 areindicative of states of the staple cartridge 3038. In certainembodiments, for example, the first and second transponder states mayindicate the unfired and fired states of the staple cartridge 3038,respectively.

At step 3310, if the first electronic state (indicative of an unfiredstaple cartridge state) is determined, the cutting instrument 3034 maybe enabled at step 3315. After the instrument 3010 is enabled, theoperator may initiate a firing operation when ready.

At step 3320, the transponder 3212, 3264 may be transitioned from thefirst electronic state to the second electronic state substantiallysimultaneously with an actuation of the cutting instrument 3034.Accordingly, if an attempt is made to reuse the staple cartridge 3038 atstep 3300, the second electronic state of the transponder 3212, 3264(indicative of the fired staple cartridge state) may be determined atstep 3310 and a firing operation consequently prevented, as shown atstep 3325.

Above-described embodiments advantageously prevent operation of theinstrument 3010 when a spent staple cartridge 3038 (or no staplecartridge 3038) is present in the end effector 3016, thus preventingcutting of tissue without simultaneous stapling. In addition topreventing operation of the instrument 3010 under such circumstances, itmay further be desirable to prevent operation of the instrument 3010after it has been used to perform a predetermined number of firingoperations. Limiting the number of firing operations may be necessary,for example, so that use of the instrument 3010 does not causeoperational lifetimes of its various components (e.g., the cuttinginstrument 3034, the battery 3104, etc.) to be exceeded.

According to various embodiments, a limit on the number of firingoperations may be implemented by the control unit 3196 using, forexample, a counter (not shown) contained within the processor 3198. Thecounter may be incremented once for each firing operation indicated byone or more sensor inputs received by the control unit 3196 (e.g.,inputs received from the end-of-stroke and beginning-of-stroke sensors3156, 3158 and the run-motor sensor 3128). Subsequent to each firingoperation, the processor 3198 may compare the counter contents to apredetermined number. The predetermined number may be stored in thememory 3200 of the processor 3198 during instrument manufacture, forexample, and represent the maximum number of firing operationsperformable by the instrument 3010. The predetermined number may bedetermined based upon, among other things, operational lifetimes of thevarious instrument components and/or the expected requirements of amedical procedure for which the instrument 3010 is to be used. When thecounted number of firing operations is equal to the predeterminednumber, the control unit 3196 may be configured to prevent additionalfiring operations by the instrument 3010. In embodiments in which thecontrol unit 3196 directly or indirectly controls rotation of the motor3106 (e.g., via a PWM signal output in response to an input from therun-motor sensor 3128), instruction code stored in the memory 3200 maycause the processor 3198 to prevent further output of power and/orcontrol signals necessary for motor operation.

In other embodiments, the control unit 3196 may prevent firingoperations in excess of the predetermined number by disabling electroniccomponents necessary for motor operation. For example, as shown in FIG.62, the control unit 3196 may be connected to the motor 3106 viaconductive leads 3268, one of which includes an electronically-actuatedfuse 3270. Subsequent to the retraction of the cutting instrument 3034after the final firing operation (e.g., when the number of firingoperations is equal to the predetermined number), the control unit 3196may cause increased current to be applied to the motor 3106 such thatthe fuse 3270 is opened (e.g., rendered non-conductive), thus preventingfurther motor operation. It will be appreciated that the placement ofthe fuse 3270 is shown by way of example only, and that the fuse 3270may be connected in other ways to effect the same result. For example,the fuse 3270 may be connected between the battery 3104 and theelectrical components of the instrument 3010. In such embodiments, whenthe number of firing operations equals the predetermined number, thecontrol unit 3196 may short circuit the fuse 3270 such that it is causedto open, thus removing power from the electrical components.

As an alternative to the fuse 3270, it will be appreciated that a switch(e.g., a relay contact) controllable by a discrete output of the controlunit 3196 may be used instead. Additionally, it will be appreciated thecontrol unit 3196 may be configured to electronically disable one ormore components necessary for motor operation (e.g., capacitors,transistors, etc.) other than a fuse by applying excessive voltagesand/or currents thereto. Such components may be internal or external tothe control unit 3196.

Although above-described embodiments for limiting instrument use utilizea counter within the processor 3198, it will be appreciated that otherembodiments may utilize an electro-mechanical counter having amechanical input suitably coupled to a component of the instrument 3010(e.g., the firing trigger 3024) such that the counter is incrementedonce for each firing operation. The counter may include a set ofelectrical contacts that close (or open) when the counted number offiring operations exceeds a predetermined number stored within thecounter. The contacts may serve as an input to the control unit 3196,and the processor 3198 may be programmed to enable or disable instrumentoperation based on the state of the contacts. Alternatively, thecontacts may be connected to other components of the instrument (e.g.,the battery 3104 or the motor 3106) such that power to the motor 3106 isinterrupted when the predetermined number of counts is exceeded.

In the embodiments described above, the battery 3104 powers (at leastpartially) the firing operation of the instrument 3010. As such, theinstrument may be a so-called “power-assist” device. More details andadditional embodiments of power-assist devices are described aredescribed in U.S. patent application Ser. No. 11/343,573 referencedabove, now U.S. Pat. No. 7,416,101, which is incorporated herein. Itshould be recognized, however, that the instrument 3010 need not be apower-assist device and that this is merely an example of a type ofdevice that may utilize aspects of the present invention. For example,the instrument 3010 may include a user display (such as a LCD or LEDdisplay) that is powered by the battery 3104 and controlled by thecontrol unit 3196. Data from the transponder 3212, 3264 in the endeffector 3016 may be displayed on such a display.

In another embodiment, the shaft 3014 of the instrument 3010, includingfor example, the proximate closure tube 3072 and the distal closure tube3074, may collectively serve as part of an antenna for the control unit3196 by radiating signals to the transponder 3212, 3264 and receivingradiated signals from the transponder 3212, 3264. That way, signals toand from the transponder 3212, 3264 in the end effector 3016 may betransmitted via the shaft 3014 of the instrument 3010.

The proximate closure tube 3072 may be grounded at its proximate end bythe exterior lower and upper side pieces 3096, 3098, which may be madeof a nonelectrically conductive material, such as plastic. The driveshaft assembly components (including the main drive shaft 3080 andsecondary drive shaft 3082) inside the proximate and distal closuretubes 3072, 3074 may also be made of a nonelectrically conductivematerial, such as plastic. Further, components of end effector 3016(such as the anvil 3028 and the channel 3026) may be electricallycoupled to (or in direct or indirect electrical contact with) the distalclosure tube 3074 such that they may also serve as part of the antenna.Further, the transponder 3212, 3264 could be positioned such that it iselectrically insulated from the components of the shaft 3014 and endeffector 3016 serving as the antenna. For example, as discussed above,the transponder 3212, 3264 may be positioned in the staple cartridge3038, which may be made of a nonelectrically conductive material, suchas plastic. Because the distal end of the shaft 3014 (such as the distalend of the distal closure tube 3074) and the portions of the endeffector 3016 serving as the antenna may be relatively close in distanceto the transponder 3212, 3264, the power for the transmitted signals maybe controlled such that interference with other systems in the useenvironment of the instrument 3010 is reduced or minimized.

In such an embodiment, as shown in FIG. 59, the control unit 3196 may beelectrically coupled to the shaft 3014 of the instrument 3010, such asto the proximate closure tube 3072, by a conductive link 3272 (e.g., awire). Portions of the outer shaft 3014, such as the closure tubes 3072,3074, may therefore act as part of an antenna for the control unit 3196by transmitting signals to the transponder 3212, 3264 and receivingsignals transmitted by the transponder 3212, 3264. Signals received bythe control unit 3196 may be demodulated by the demodulator 3204 anddecoded by the decoder 3206, as described above.

To transmit data signals to or from the transponder 3212, 3264 in theend effector 3016, the link 3272 may connect the control unit 3196 tocomponents of the shaft 3014 of the instrument 3010, such as theproximate closure tube 3072, which may be electrically connected to thedistal closure tube 3074. The distal closure tube 3074 is preferablyelectrically insulated from the transponder 3212, 3264, which may bepositioned in the plastic staple cartridge 3038. As mentioned before,components of the end effector 3016, such as the channel 3026 and theanvil 3028, may be conductive and in electrical contact with the distalclosure tube 3074 such that they, too, may serve as part of the antenna.

With the shaft 3014 acting as the antenna for the control unit 3196, thecontrol unit 3196 can communicate with the transponder 3212, 3264 in theend effector 3016 without a hardwired connection. In addition, becausethe distance between shaft 3014 and the transponder 3212, 3264 is fixedand known, the power levels could be optimized to thereby minimizeinterference with other systems in the use environment of the instrument3010.

In another embodiment, the components of the shaft 3014 and/or the endeffector 3016 may serve as an antenna for the transponder 3212, 3264. Insuch an embodiment, the transponder 3212, 3264 is electrically connectedto the shaft 3014 (such as to distal closure tube 3074, which may beelectrically connected to the proximate closure tube 3072) and thecontrol unit 3196 is insulated from the shaft 3014. For example, thetransponder 3212, 3264 could be connected to a conductive component ofthe end effector 3016 (such as the channel 3026), which in turn may beconnected to conductive components of the shaft (e.g., the closure tubes3072, 3074). Alternatively, the end effector 3016 may include a wire(not shown) that connects the transponder 3212, 3264 the distal closuretube 3074.

FIGS. 64 and 65 depict a surgical cutting and fastening instrument 4010according to various embodiments of the present invention. Theillustrated embodiment is an endoscopic instrument and, in general, theembodiments of the instrument 4010 described herein are endoscopicsurgical cutting and fastening instruments. It should be noted, however,that according to other embodiments of the present invention, theinstrument may be a non-endoscopic surgical cutting and fasteninginstrument, such as a laparoscopic instrument.

The surgical instrument 4010 depicted in FIGS. 64 and 65 comprises ahandle 4012, a shaft 4014, and an articulating end effector 4016pivotally connected to the shaft 4014 at an articulation pivot 4018. Anarticulation control 4020 may be provided adjacent to the handle 4012 toeffect rotation of the end effector 4016 about the articulation pivot4018. In the illustrated embodiment, the end effector 4016 is configuredto act as an endocutter for clamping, severing and stapling tissue,although, in other embodiments, different types of end effectors may beused, such as end effectors for other types of surgical devices, such asgraspers, cutters, staplers, clip appliers, access devices, drug/genetherapy devices, ultrasound, RF or laser devices, etc.

The handle 4012 of the instrument 4010 may include a closure trigger4022 and a firing trigger 4024 for actuating the end effector 4016. Itwill be appreciated that instruments having end effectors directed todifferent surgical tasks may have different numbers or types of triggersor other suitable controls for operating the end effector 4016. The endeffector 4016 is shown separated from the handle 4012 by a preferablyelongate shaft 4014. In one embodiment, an operator of the instrument4010 may articulate the end effector 4016 relative to the shaft 4014 byutilizing the articulation control 4020 as described in more detail inU.S. patent application Ser. No. 11/329,020, entitled SURGICALINSTRUMENT HAVING AN ARTICULATING END EFFECTOR, now U.S. Pat. No.7,670,334, which is incorporated herein by reference.

The end effector 4016 includes in this example, among other things, astaple channel 4026 and a pivotally translatable clamping member, suchas an anvil 4028, which are maintained at a spacing that assureseffective stapling and severing of tissue clamped in the end effector4016. The handle 4012 includes a pistol grip 4030 towards which aclosure trigger 4022 is pivotally drawn by the operator to causeclamping or closing of the anvil 4028 toward the staple channel 4026 ofthe end effector 4016 to thereby clamp tissue positioned between theanvil 4028 and the channel 4026. The firing trigger 4024 is fartheroutboard of the closure trigger 4022. Once the closure trigger 4022 islocked in the closure position as further described below, the firingtrigger 4024 may rotate slightly toward the pistol grip 4030 so that itcan be reached by the operator using one hand. The operator may thenpivotally draw the firing trigger 4024 toward the pistol grip 4030 tocause the stapling and severing of clamped tissue in the end effector4016. In other embodiments, different types of clamping members besidesthe anvil 4028 may be used, such as, for example, an opposing jaw, etc.

It will be appreciated that the terms “proximal” and “distal” are usedherein with reference to an operator gripping the handle 4012 of aninstrument 4010. Thus, the end effector 4016 is distal with respect tothe more proximal handle 4012. It will be further appreciated that, forconvenience and clarity, spatial terms such as “vertical” and“horizontal” are used herein with respect to the drawings. However,surgical instruments are used in many orientations and positions, andthese terms are not intended to be limiting and absolute.

The closure trigger 4022 may be actuated first. Once the operator issatisfied with the positioning of the end effector 4016, the operatormay draw back the closure trigger 4022 to its fully closed, lockedposition proximate to the pistol grip 4030. The firing trigger 4024 maythen be actuated. The firing trigger 4024 returns to the open position(shown in FIGS. 64 and 65) when the operator removes pressure, asdescribed more fully below. A release button 4032 on the handle 4012,when depressed, may release the locked closure trigger 4022. Variousconfigurations for locking and unlocking the closure trigger 4022 usingthe release button 4032 are described in U.S. patent application Ser.No. 11/343,573, entitled MOTOR-DRIVEN SURGICAL CUTTING AND FASTENINGINSTRUMENT WITH LOADING FORCE FEEDBACK, now U.S. Pat. No. 7,416,101,which is incorporated herein by reference.

FIG. 66A is an exploded view of the end effector 4016 according tovarious embodiments. As shown in the illustrated embodiment, the endeffector 4016 may include, in addition to the previously-mentionedchannel 4026 and anvil 4028, a cutting instrument 4034, a sled 4036, astaple cartridge 4038 that is removably seated (e.g., installed) in thechannel 4026, and a helical screw shaft 4040, and FIG. 66B is aperspective view of the cutting instrument of FIG. 66A.

The anvil 4028 may be pivotably opened and closed at a pivot point 4042connected to the proximate end of the channel 4026. The anvil 4028 mayalso include a tab 4044 at its proximate end that is inserted into acomponent of the mechanical closure system (described further below) toopen and close the anvil 4028. When the closure trigger 4022 isactuated, that is, drawn in by an operator of the instrument 4010, theanvil 4028 may pivot about the pivot point 4042 into the clamped orclosed position. If clamping of the end effector 4016 is satisfactory,the operator may actuate the firing trigger 4024, which, as explained inmore detail below, causes the cutting instrument 4034 to travellongitudinally along the channel 4026.

As shown, the cutting instrument 4034 includes upper guide pins 4046that enter an anvil slot 4048 in the anvil 4028 to verify and assist inmaintaining the anvil 4028 in a closed state during staple formation andsevering. Spacing between the channel 4026 and anvil 4028 is furthermaintained by the cutting instrument 4034 by having middle pins 4050slide along the top surface of the channel 4026 while a bottom foot 4052opposingly slides along the undersurface of the channel 4026, guided bya longitudinal opening 4054 in the channel 4026. A distally presentedcutting surface 4056 between the upper guide pins 4046 and middle pins4050 severs clamped tissue while distally-presented surface 4058actuates the staple cartridge 4038 by progressively driving the sled4036 from an unfired position to a fired position. Actuation of thestaple cartridge 4038 causes staple drivers 4060 to cam upwardly,driving staples 4062 out of upwardly open staple holes 4064 formed inthe staple cartridge 4038. The staples 4062 are subsequently formedagainst a staple forming undersurface 4066 of the anvil 4028. A staplecartridge tray 4068 encompasses from the bottom the other components ofthe staple cartridge 4038 to hold them in place. The staple cartridgetray 4068 includes a rearwardly open slot 4070 that overlies thelongitudinal opening 4054 in the channel 4026. A lower surface of thestaple cartridge 4038 and an upward surface of the channel 4026 form afiring drive slot 4200 (FIG. 69) through which the middle pins 4050 passduring distal and proximal movement of the cutting instrument 4034. Thesled 4036 may be an integral component of the staple cartridge 4038 suchthat when the cutting instrument 4034 retracts following the cuttingoperation, the sled 4036 does not retract. U.S. Pat. No. 6,978,921,entitled SURGICAL STAPLING INSTRUMENT INCORPORATING AN E-BEAM FIRINGMECHANISM, which is incorporated herein by reference, provides moredetails about such two-stroke cutting and fastening instruments.

It should be noted that although the embodiments of the instrument 4010described herein employ an end effector 4016 that staples the severedtissue, in other embodiments different techniques for fastening orsealing the severed tissue may be used. For example, end effectors thatuse RF energy or adhesives to fasten the severed tissue may also beused. U.S. Pat. No. 5,709,680, entitled ELECTROSURGICAL HEMOSTATICDEVICE, and U.S. Pat. No. 5,688,270, entitled ELECTROSURGICAL HEMOSTATICDEVICE WITH RECESSED AND/OR OFFSET ELECTRODES, both of which areincorporated herein by reference, disclose cutting instruments that useRF energy to fasten the severed tissue. U.S. patent application Ser. No.11/267,811, entitled SURGICAL STAPLING INSTRUMENTS STRUCTURED FORDELIVERY OF MEDICAL AGENTS, now U.S. Pat. No. 7,673,783, and U.S. patentapplication Ser. No. 11/267,383, entitled SURGICAL STAPLING INSTRUMENTSSTRUCTURED FOR PUMP-ASSISTED DELIVERY OF MEDICAL AGENTS, now U.S. Pat.No. 7,607,557, both of which are also incorporated herein by reference,disclose cutting instruments that use adhesives to fasten the severedtissue. Accordingly, although the description herein refers tocutting/stapling operations and the like, it should be recognized thatthis is an exemplary embodiment and is not meant to be limiting. Othertissue-fastening techniques may also be used.

FIGS. 67 and 68 are exploded views and FIG. 69 is a side view of the endeffector 4016 and shaft 4014 according to various embodiments. As shownin the illustrated embodiment, the shaft 4014 may include a proximateclosure tube 4072 and a distal closure tube 4074 pivotably linked by apivot links 4076. The distal closure tube 4074 includes an opening 4078into which the tab 4044 on the anvil 4028 is inserted in order to openand close the anvil 4028, as further described below. Disposed insidethe closure tubes 4072, 4074 may be a proximate spine tube 4079.Disposed inside the proximate spine tube 4079 may be a main rotational(or proximate) drive shaft 4080 that communicates with a secondary (ordistal) drive shaft 4082 via a bevel gear assembly 4084. The secondarydrive shaft 4082 is connected to a drive gear 4086 that engages aproximate drive gear 4088 of the helical screw shaft 4040. The verticalbevel gear 4084 b may sit and pivot in an opening 4090 in the distal endof the proximate spine tube 4079. A distal spine tube 4092 may be usedto enclose the secondary drive shaft 4082 and the drive gears 4086,4088. Collectively, the main drive shaft 4080, the secondary drive shaft4082, and the articulation assembly (e.g., the bevel gear assembly 4084a-c) are sometimes referred to herein as the “main drive shaftassembly.”

A bearing 4094 (FIG. 69) positioned at a distal end of the staplechannel 4026 receives the helical screw shaft 4040, allowing the helicalscrew shaft 4040 to freely rotate with respect to the channel 4026. Thehelical screw shaft 4040 may interface a threaded opening (not shown) ofthe cutting instrument 4034 such that rotation of the helical screwshaft 4040 causes the cutting instrument 4034 to translate distally orproximately (depending on the direction of the rotation) through thestaple channel 4026. Accordingly, when the main drive shaft 4080 iscaused to rotate by actuation of the firing trigger 4024 (as explainedin further detail below), the bevel gear assembly 4084 a-c causes thesecondary drive shaft 4082 to rotate, which in turn, because of theengagement of the drive gears 4086, 4088, causes the helical screw shaft4040 to rotate, which causes the cutting instrument 4034 to travellongitudinally along the channel 4026 to cut any tissue clamped withinthe end effector 4016. The sled 4036 may be made of, for example,plastic, and may have a sloped distal surface. As the sled 4036traverses the channel 4026, the sloped distal surface may cam the stapledrivers 4060 upward, which in turn push up or drive the staples 4062 inthe staple cartridge 4038 through the clamped tissue and against thestaple forming undersurface 4066 of the anvil 4028, thereby stapling thesevered tissue. When the cutting instrument 4034 is retracted, thecutting instrument 4034 and the sled 4036 may become disengaged, therebyleaving the sled 4036 at the distal end of the channel 4026.

FIGS. 70-73 illustrate an exemplary embodiment of a motor-drivenendocutter, and in particular the handle 4012 thereof, that providesoperator-feedback regarding the deployment and loading force of thecutting instrument 4034 in the end effector 4016. In addition, theembodiment may use power provided by the operator in retracting thefiring trigger 4024 to power the device (a so-called “power assist”mode). As shown in the illustrated embodiment, the handle 4012 includesexterior lower side pieces 4096, 4098 and exterior upper side pieces4100, 4102 that fit together to form, in general, the exterior of thehandle 4012. A battery 4104 may be provided in the pistol grip portion4030 of the handle 4012. The battery 4104 may be constructed accordingto any suitable construction or chemistry including, for example, aLi-ion chemistry such as LiCoO₂ or LiNiO₂, a Nickel Metal Hydridechemistry, etc. The battery 4104 powers a motor 4106 disposed in anupper portion of the pistol grip portion 4030 of the handle 4012.According to various embodiments, the motor 4106 may be a DC brusheddriving motor having a maximum rotation of approximately 5000 to 100,000RPM. The motor 4106 may drive a 90-degree bevel gear assembly 4108comprising a first bevel gear 4110 and a second bevel gear 4112. Thebevel gear assembly 4108 may drive a planetary gear assembly 4114. Theplanetary gear assembly 4114 may include a pinion gear 4116 connected toa drive shaft 4118. The pinion gear 4116 may drive a mating ring gear4120 that drives a helical gear drum 4122 via a drive shaft 4124. A ring4126 may be threaded on the helical gear drum 4122. Thus, when the motor4106 rotates, the ring 4126 is caused to travel along the helical geardrum 4122 by means of the interposed bevel gear assembly 4108, planetarygear assembly 4114 and ring gear 4120.

The handle 4012 may also include a run motor sensor 4128 incommunication with the firing trigger 4024 to detect when the firingtrigger 4024 has been drawn in (or “closed”) toward the pistol gripportion 4030 of the handle 4012 by the operator to thereby actuate thecutting/stapling operation by the end effector 4016. The sensor 4128 maybe a proportional sensor such as, for example, a rheostat or variableresistor. When the firing trigger 4024 is drawn in, the sensor 4128detects the movement, and sends an electrical signal indicative of thevoltage (or power) to be supplied to the motor 4106. When the sensor4128 is a variable resistor or the like, the rotation of the motor 4106may be generally proportional to the amount of movement of the firingtrigger 4024. That is, if the operator only draws or closes the firingtrigger 4024 in a little bit, the rotation of the motor 4106 isrelatively low. When the firing trigger 4024 is fully drawn in (or inthe fully closed position), the rotation of the motor 4106 is at itsmaximum. In other words, the harder the operator pulls on the firingtrigger 4024, the more voltage is applied to the motor 4106, causing agreater rate of rotation. In another embodiment, for example, amicrocontroller (e.g., the microcontroller 4250 of FIG. 92) may output aPWM control signal to the motor 4106 based on the input from the sensor4128 in order to control the motor 4106.

The handle 4012 may include a middle handle piece 4130 adjacent to theupper portion of the firing trigger 4024. The handle 4012 also maycomprise a bias spring 4132 connected between posts on the middle handlepiece 4130 and the firing trigger 4024. The bias spring 4132 may biasthe firing trigger 4024 to its fully open position. In that way, whenthe operator releases the firing trigger 4024, the bias spring 4132 willpull the firing trigger 4024 to its open position, thereby removingactuation of the sensor 4128, thereby stopping rotation of the motor4106. Moreover, by virtue of the bias spring 4132, any time an operatorcloses the firing trigger 4024, the operator will experience resistanceto the closing operation, thereby providing the operator with feedbackas to the amount of rotation exerted by the motor 4106. Further, theoperator could stop retracting the firing trigger 4024 to thereby removeforce from the sensor 4128, to thereby stop the motor 4106. As such, theoperator may stop the deployment of the end effector 4016, therebyproviding a measure of control of the cutting/fastening operation to theoperator.

The distal end of the helical gear drum 4122 includes a distal driveshaft 4134 that drives a ring gear 4136, which mates with a pinion gear4138. The pinion gear 4138 is connected to the main drive shaft 4080 ofthe main drive shaft assembly. In that way, rotation of the motor 4106causes the main drive shaft assembly to rotate, which causes actuationof the end effector 4016, as described above.

The ring 4126 threaded on the helical gear drum 4122 may include a post4140 that is disposed within a slot 4142 of a slotted arm 4144. Theslotted arm 4144 has an opening 4146 its opposite end 4148 that receivesa pivot pin 4150 that is connected between the handle exterior sidepieces 4096, 4098. The pivot pin 4150 is also disposed through anopening 4152 in the firing trigger 4024 and an opening 4154 in themiddle handle piece 4130.

In addition, the handle 4012 may include a reverse motor (orend-of-stroke) sensor 4156 and a stop motor (or beginning-of-stroke)sensor 4158. In various embodiments, the reverse motor sensor 4156 maybe a normally-open limit switch located at the distal end of the helicalgear drum 4122 such that the ring 4126 threaded on the helical gear drum4122 contacts and closes the reverse motor sensor 4156 when the ring4126 reaches the distal end of the helical gear drum 4122. The reversemotor sensor 4156, when closed, sends a signal to the motor 4106 toreverse its rotation direction, thereby retracting the cuttinginstrument 4034 of the end effector 4016 following a cutting operation.

The stop motor sensor 4158 may be, for example, a normally-closed limitswitch. In various embodiments, it may be located at the proximate endof the helical gear drum 4122 so that the ring 4126 opens the switch4158 when the ring 4126 reaches the proximate end of the helical geardrum 4122.

In operation, when an operator of the instrument 4010 pulls back thefiring trigger 4024, the sensor 4128 detects the deployment of thefiring trigger 4024 and sends a signal to the motor 4106 to causeforward rotation of the motor 4106 at, for example, a rate proportionalto how hard the operator pulls back the firing trigger 4024. The forwardrotation of the motor 4106 in turn causes the ring gear 4120 at thedistal end of the planetary gear assembly 4114 to rotate, therebycausing the helical gear drum 4122 to rotate, causing the ring 4126threaded on the helical gear drum 4122 to travel distally along thehelical gear drum 4122. The rotation of the helical gear drum 4122 alsodrives the main drive shaft assembly as described above, which in turncauses deployment of the cutting instrument 4034 in the end effector4016. That is, the cutting instrument 4034 and sled 4036 are caused totraverse the channel 4026 longitudinally, thereby cutting tissue clampedin the end effector 4016. Also, the stapling operation of the endeffector 4016 is caused to happen in embodiments where a stapling-typeend effector is used.

By the time the cutting/stapling operation of the end effector 4016 iscomplete, the ring 4126 on the helical gear drum 4122 will have reachedthe distal end of the helical gear drum 4122, thereby causing thereverse motor sensor 4156 to be actuated, which sends a signal to themotor 4106 to cause the motor 4106 to reverse its rotation. This in turncauses the cutting instrument 4034 to retract, and also causes the ring4126 on the helical gear drum 4122 to move back to the proximate end ofthe helical gear drum 4122.

The middle handle piece 4130 includes a backside shoulder 4160 thatengages the slotted arm 4144 as best shown in FIGS. 71 and 72. Themiddle handle piece 4130 also has a forward motion stop 4162 thatengages the firing trigger 4024. The movement of the slotted arm 4144 iscontrolled, as explained above, by rotation of the motor 4106. When theslotted arm 4144 rotates CCW as the ring 4126 travels from the proximateend of the helical gear drum 4122 to the distal end, the middle handlepiece 4130 will be free to rotate CCW. Thus, as the operator draws inthe firing trigger 4024, the firing trigger 4024 will engage the forwardmotion stop 4162 of the middle handle piece 4130, causing the middlehandle piece 4130 to rotate CCW. Due to the backside shoulder 4160engaging the slotted arm 4144, however, the middle handle piece 4130will only be able to rotate CCW as far as the slotted arm 4144 permits.In that way, if the motor 4106 should stop rotating for some reason, theslotted arm 4144 will stop rotating, and the operator will not be ableto further draw in the firing trigger 4024 because the middle handlepiece 4130 will not be free to rotate CCW due to the slotted arm 4144.

FIGS. 74 and 75 illustrate two states of a variable sensor that may beused as the run motor sensor 4128 according to various embodiments ofthe present invention. The sensor 4128 may include a face portion 4164,a first electrode (A) 4166, a second electrode (B) 4168, and acompressible dielectric material 4170 (e.g., EAP) between the electrodes4166, 4168. The sensor 4128 may be positioned such that the face portion4164 contacts the firing trigger 4024 when retracted. Accordingly, whenthe firing trigger 4024 is retracted, the dielectric material 4170 iscompressed, as shown in FIG. 75, such that the electrodes 4166, 4168 arecloser together. Since the distance “b” between the electrodes 4166,4168 is directly related to the impedance between the electrodes 4166,4168, the greater the distance the more impedance, and the closer thedistance the less impedance. In that way, the amount that the dielectricmaterial 4170 is compressed due to retraction of the firing trigger 4024(denoted as force “F” in FIG. 75) is proportional to the impedancebetween the electrodes 4166, 4168, which can be used to proportionallycontrol the motor 4106.

Components of an exemplary closure system for closing (or clamping) theanvil 4028 of the end effector 4016 by retracting the closure trigger4022 are also shown in FIGS. 70-73. In the illustrated embodiment, theclosure system includes a yoke 4172 connected to the closure trigger4022 by a pin 4174 that is inserted through aligned openings in both theclosure trigger 4022 and the yoke 4172. A pivot pin 4176, about whichthe closure trigger 4022 pivots, is inserted through another opening inthe closure trigger 4022 which is offset from where the pin 4174 isinserted through the closure trigger 4022. Thus, retraction of theclosure trigger 4022 causes the upper part of the closure trigger 4022,to which the yoke 4172 is attached via the pin 4174, to rotate CCW. Thedistal end of the yoke 4172 is connected, via a pin 4178, to a firstclosure bracket 4180. The first closure bracket 4180 connects to asecond closure bracket 4182. Collectively, the closure brackets 4180,4182 define an opening in which the proximal end of the proximateclosure tube 4072 (see FIG. 67) is seated and held such thatlongitudinal movement of the closure brackets 4180, 4182 causeslongitudinal motion by the proximate closure tube 4072. The instrument4010 also includes a closure rod 4184 disposed inside the proximateclosure tube 4072. The closure rod 4184 may include a window 4186 intowhich a post 4188 on one of the handle exterior pieces, such as exteriorlower side piece 4096 in the illustrated embodiment, is disposed tofixedly connect the closure rod 4184 to the handle 4012. In that way,the proximate closure tube 4072 is capable of moving longitudinallyrelative to the closure rod 4184. The closure rod 4184 may also includea distal collar 4190 that fits into a cavity 4192 in proximate spinetube 4079 and is retained therein by a cap 4194 (see FIG. 67).

In operation, when the yoke 4172 rotates due to retraction of theclosure trigger 4022, the closure brackets 4180, 4182 cause theproximate closure tube 4072 to move distally (i.e., away from the handle4012 of the instrument 4010), which causes the distal closure tube 4074to move distally, which causes the anvil 4028 to rotate about the pivotpoint 4042 into the clamped or closed position. When the closure trigger4022 is unlocked from the locked position, the proximate closure tube4072 is caused to slide proximally, which causes the distal closure tube4074 to slide proximally, which, by virtue of the tab 4044 beinginserted in the opening 4078 of the distal closure tube 4074, causes theanvil 4028 to pivot about the pivot point 4042 into the open orunclamped position. In that way, by retracting and locking the closuretrigger 4022, an operator may clamp tissue between the anvil 4028 andchannel 4026, and may unclamp the tissue following the cutting/staplingoperation by unlocking the closure trigger 4022 from the lockedposition.

According to various embodiments, the instrument 4010 may include aninterlock for preventing instrument 4010 operation when the staplecartridge 4038 is not installed in the channel 4026, or when the staplecartridge 4038 is installed in the channel 4026 but spent. Operation ofthe interlock is twofold. First, in the absence of an unspent staplecartridge 4038 within the channel 4026, the interlock operates tomechanically block distal advancement of the cutting instrument 4034through the channel 4026 in response to actuation of the firing trigger4024. Using suitable electronics disposed within the handle 4012, theinterlock next detects the increase in current through the motor 4106resulting from the immobilized cutting instrument 4034 and consequentlyinterrupts current to the motor 4106. Advantageously, the interlockeliminates the need for electronic sensors in the end effector 4016,thus simplifying instrument design. Moreover, because the magnitude andduration of mechanical blocking force needed to produce the detectedincrease in motor current is significantly less than that which would beexerted if only a conventional mechanical interlock was used, physicalstresses experienced by instrument components are reduced.

According to various embodiments, the interlock may include (1) ablocking mechanism to prevent actuation of the cutting instrument 4034by the motor 4106 when an unspent staple cartridge 4038 is not installedin the channel 4026, and (2) a lockout circuit to detect the currentthrough the motor 4106 and to interrupt the current through the motor4106 based on the sensed current.

FIG. 94 is a flow diagram of the process implemented by the interlockaccording to various embodiments. At step 4264, the actuation of thecutting instrument 4034 by the motor 4106 is mechanically blocked by theblocking mechanism in the absence of an unspent staple cartridge 4038within the channel 4026. As discussed below, the blocking mechanism mayinclude components or features of conventional mechanical interlocks.

At step 4266, the current through the motor 4106 resulting from theblocked actuation of the cutting instrument 4034 is detected by thelockout circuit. As discussed below, detection of the current mayinclude, for example, the steps of sensing the motor current, generatinga signal representative of the sensed motor current, and comparing thegenerated signal to a threshold signal.

At step 4268, the current through the motor 4106 is interrupted based onthe detected current. Interrupting the current may include, for example,interrupting the current when the result of the comparison at step 4266indicates that the generated signal exceeds the threshold signal.Interrupting the current through the motor 4106 may further includeinterrupting the current based on a position of the cutting instrument4034.

According to various embodiments, the blocking mechanism of theinterlock may include features similar or identical to those ofconventional mechanical interlocks for physically blocking advancementof the cutting instrument 4034 in the absence of an unspent staplecartridge 4038 within the channel 4026. FIG. 76 illustrates a blockingmechanism 4196 according to one embodiment. As shown, the blockingmechanism 4196 may comprise a pair of spring fingers 4198 positioned inthe channel 4026. In particular, the spring fingers 4196 may raise up toblock the middle pins 4050 of the cutting instrument 4034 when the sled4036 (not shown in FIG. 76) is not present in an unfired position at theproximal end of the channel 4026, such as when the staple cartridge 4038is not installed or when the staple cartridge 4038 is installed butspent. Although two spring fingers 4198 are shown, it will beappreciated that more or fewer spring fingers 4198 may be used instead.

FIGS. 77-80 depict the operation of the spring fingers 4198 sequentiallyas the instrument 4010 is fired. In FIG. 77, an unspent staple cartridge4038 has been inserted into the channel 4026. The presence of the sled4036 in its unfired position depresses the spring fingers 4198 such thatthe firing drive slot 4200 through which the middle pins 4050 will passis unimpeded.

In FIG. 78, firing of the staple cartridge 4038 has commenced, with thesled 4036 and the middle pins 4050 of the cutting instrument 4034 havingdistally traversed off of the spring fingers 4198, which then spring upinto the firing drive slot 4200.

In FIG. 79, the staple cartridge 4038 is now spent with the sled 4036fully driven distally and no longer depicted. The cutting instrument4034 is being retracted proximally. Since the spring fingers 4198 pivotfrom a more distal point, the middle pins 4050 of the cutting instrument4034 are able to ride up onto the spring fingers 4198 during retraction,causing them to be depressed out of the firing drive slot 4200.

In FIG. 80, the cutting instrument 4034 is fully retracted and nowconfronts the non-depressed pair of spring fingers 4198 to preventdistal movement. The blocking mechanism 4196 thereby remains activateduntil an unspent staple cartridge 4038 is installed in the channel 4026.

FIG. 81 depicts a blocking mechanism 4202 according to anotherembodiment. The blocking mechanism 4202, which is disclosed in U.S. Pat.No. 7,044,352 referenced above, includes a pair of hooks 4204 havingramped ends 4206 distally placed with regard to attachment devices 4208.The attachment devices 4208 are inserted through apertures 4210 in thechannel 4026, thereby springedly attaching the hooks 4204 to the channel4026. The ramped ends 4206 lie above a hook recess 4212 defined in thechannel 4026. Thus, when each ramped end 4206 is contacted by the sled4036 of an unspent staple cartridge 4038 (not shown in FIG. 81), theramped ends 4206 are depressed into the hook recess 4212, therebyclearing the way for the middle pins 4050 of the cutting instrument 4034to move distally through the firing drive slot 4200 so that the staplecartridge 4038 may be actuated. A thin shaft 4214 coupling theattachment devices 4208 respectively to the ramped end 4206 of each hook4204 resiliently responds to absence of the sled 4036, as depicted,wherein the ramped ends 4206 return to impede the firing drive slot 4200to block the retracted middle pins 4050 of the cutting instrument 4034.Although two hooks 4204 are shown, it will be appreciated that more orfewer hooks 4204 may be used instead.

FIGS. 82-85 depict the sequence of operation of the hooks 4204. In FIG.82, the staple cartridge 4038 is unspent so that the distally positionedsled 4036 depresses the ramped ends 4206 into the hook recess 4212,allowing the middle pins 4050 of the cutting instrument 4034 to movedistally through the firing drive slot 4200 during firing, as depictedin FIG. 83. With the sled 4036 and middle pins 4050 distally removedwith respect to the blocking mechanism 4202, the ramped ends 4206resiliently raise out of the hook recess 4212 to occupy the firing driveslot 4200.

In FIG. 84, the cutting instrument 4034 is being retracted to the pointof contacting the ramped ends 4206 of the hooks 4204. Since the distalend of the ramped ends 4206 is lower than the proximal part of theramped ends 4206, the middle pins 4050 of the cutting instrument 4034ride over the ramped ends 4206, forcing them down into the hook recess4212 until the middle pins 4050 are past the ramped ends 4206, asdepicted in FIG. 85, wherein the ramped ends 4206 resiliently springback up to block the middle pins 4050. Thus, the cutting instrument 4034is prevented from distal movement until an unspent staple cartridge 4038is installed in the channel 4026.

FIG. 86 depicts a blocking mechanism 4216 according to yet anotherembodiment. The blocking mechanism 4216 is integrally formed with thestaple cartridge 4038 and includes proximally projecting blockingmembers 4218 resiliently positioned above the sled 4036 (not shown inFIG. 86). In particular, the blocking members 4218 each reside within adownward and proximally opening cavity 4220. Each blocking member 4218includes a leaf spring end 4222 that is held within the cavity 4220.

The cavities 4220 are vertically aligned and spaced and parallel about aproximally presented vertical slot 4224 in the staple cartridge 4038through which the cutting surface 4056 (not shown in FIG. 86) passes.The staple cartridge 4038 also includes slots 4226 that longitudinallypass through the staple cartridge 4038, being open from a portion of aproximal and underside of the staple cartridge 4038 to receive the sled4036.

Each blocking member 4218 has a deflectable end 4228 having a rampeddistal side 4227 and blocking proximal side 4229. The blocking members4218 are shaped to reside within their respective cavities 4220 whendepressed and to impede the distally moving middle pins 4050 of thecutting instrument 4034 when released.

FIGS. 87-90 depict the blocking mechanism 4216 sequentially as theinstrument 4010 is fired. In FIG. 87, an unspent staple cartridge 4038has been inserted into the channel 4026 with the sled 4036 depressingupward the deflectable ends 4228 so that the firing drive slot 4200 isunimpeded.

In FIG. 88, firing of the staple cartridge 4038 has commenced, with thesled 4036 and the middle pins 4050 of the cutting instrument 4034 havingdistally traversed past the deflectable ends 4228, which then springdown into the firing drive slot 4200.

In FIG. 89, the staple cartridge 4038 is now spent with the sled 4036fully driven distally and no longer depicted. The cutting instrument4034 is being retracted proximally. Since the deflectable ends 4228pivot from a more distal point, the middle pins 4050 of the cuttinginstrument 4034 are able to ride under the ramped distal sides 4227 ofthe deflectable ends 4228 during retraction, causing them to bedepressed up, out of the firing drive slot 4200.

In FIG. 90, the cutting instrument 4034 is fully retracted and themiddle pints 4050 now confront the blocking proximal sides 4229 of thenon-depressed (released) pair of deflectable ends 4228 to prevent distalmovement. The blocking mechanism 4216 thereby remains activated until anunspent staple cartridge 4038 is installed in the channel 4026.

The blocking mechanisms 4196, 4202, 4216 of the above-discussedembodiments are provided by way of example only. It will be appreciatedthat other suitable blocking mechanisms may be used instead.

FIG. 91 is a schematic diagram of an electrical circuit 4231 of theinstrument 4010 according to various embodiments of the presentinvention. In certain embodiments, the circuit 4231 may be housed withinthe handle 4012. In addition to the sensor 4128, sensors 4156, 4158(depicted as a normally-open limit switch and a normally-closed limitswitch, respectively), the battery 4104, and the motor 4106, the circuit4231 may include a single-pole double-throw relay 4230, a single-polesingle-throw relay 4232, a double-pole double-throw relay 4234, acurrent sensor 4236, a position sensor 4238, and a current detectionmodule 4240. Relay 4232, the current sensor 4236, the position sensor4238, and the current detection module 4240 collectively form a lockoutcircuit 4241. As described below, the lockout circuit 4241 operates tosense the current through the motor 4106 and to interrupt the currentbased upon the sensed current, thus “locking out” the instrument 4010 bydisabling its operation.

As described above, sensor 4128 is activated when an operator pulls inthe firing trigger 4024 after locking the closure trigger 4022. Whenswitch 4156 is open (indicating that the cutting/stapling operation ofthe end effector 4016 is not yet complete), coil 4242 of relay 4230 isde-energized, thus forming a conductive path between the battery 4104and relay 4232 via a normally-closed contact of relay 4230. Coil 4244 ofrelay 4232 is controlled by the current detection module 4240 and theposition sensor 4238 as described below. When coil 4244 is de-energizedand coil 4242 is de-energized, a conductive path between the battery4104 and a normally-closed contact of relay 4234 is formed. Relay 4234controls the rotational direction of the motor 4106 based on the statesof switches 4156, 4158. When switch 4156 is open and switch 4158 isclosed (indicating that the cutting instrument 4034 has not yet fullydeployed distally), coil 4246 of relay 4234 is de-energized.Accordingly, when coils 4242, 4244, 4246 are collectively de-energized,current from the battery 4104 flows through the motor 4106 via thenormally-closed contacts of relay 4234 and causes the forward rotationof the motor 4106, which in turn causes distal deployment of the cuttinginstrument 4034 as described above.

When switch 4156 is closed (indicating that the cutting instrument 4034has fully deployed distally), coil 4242 of relay 4230 is energized, andcoil 4246 of relay 4234 is energized via a normally-open contact ofrelay 4230. Accordingly, current now flows to the motor 4106 vianormally-open contacts of relays 4230, 4234, thus causing reverserotation of the motor 4106 which in turn causes the cutting instrument4034 to retract from its distal position and switch 4156 to open. Coil4242 of relay 4230 remains energized until limit switch 4158 is opened,indicating the complete retraction of the cutting instrument 4034.

The magnitude of current through the motor 4106 during its forwardrotation is indicative of forces exerted upon the cutting instrument4034 during its deployment. As described above, the absence of anunspent staple cartridge 4038 in the channel 4026 (e.g., the presence ofa spent staple cartridge 4038 or the absence of a staple cartridge 4038altogether) results in activation of the blocking mechanism 4196, 4202,4216 such that distal movement of the cutting instrument 4034 isprevented. The resistive force exerted by the blocking mechanism 4196,4202, 4216 against the cutting instrument 4034 causes an increase inmotor torque, thus causing motor current to increase to a level that ismeasurably greater than that present during a cutting and staplingoperation. Accordingly, by sensing the current through the motor 4106,the lockout circuit 4241 may differentiate between deployment of thecutting instrument 4034 when an unspent cartridge 4038 is installed inthe channel 4026 versus deployment of the cutting instrument 4034 whenan unspent cartridge 4038 is absent from the channel 4026.

The current sensor 4236 may be coupled to a path of the circuit 4231that conducts current to the motor 4106 during its forward rotation. Thecurrent sensor 4236 may be any current sensing device (e.g., a shuntresistor, a Hall effect current transducer, etc.) suitable forgenerating a signal (e.g., a voltage signal) representative of sensedmotor current. The generated signal may be input to the currentdetection module 4240 for processing therein, as described below.

According to various embodiments, the current detection module 4240 maybe configured for comparing the signal generated by the current sensor4236 to a threshold signal (e.g., a threshold voltage signal) todetermine if the blocking mechanism 4196, 4202, 4216 has been activated.For a given instrument 4010, a suitable value of the threshold signalmay be empirically determined a priori by, for example, measuring thepeak signal generated by the current sensor 4236 when the cuttinginstrument 4034 is initially deployed (e.g., over the first 0.06 inchesof its distal movement) during a cutting and stapling operation, andwhen the cutting instrument 4034 is deployed and encounters theactivated blocking mechanism 4196, 4202, 4216. The threshold signalvalue may be selected to be less than the peak signal measured when theblocking mechanism 4196, 4202, 4216 is activated, but larger than thepeak signal measured during a cutting and stapling operation.

In certain embodiments and as shown in FIG. 91, the current detectionmodule 4240 may comprise a comparator circuit 4248 for receiving thethreshold and current sensor 4236 signals and generating a discreteoutput based on a comparison of the received signals. For example, thecomparator circuit 4248 may generate a 5 VDC output when the thresholdsignal is exceeded and a OVDC output when the threshold signal is notexceeded. The threshold signal may be generated, for example, using asuitable signal reference circuit (e.g., a voltage reference circuit)(not shown). The design and operation of the comparator circuit 4248 andsignal reference circuit are well known in the art and are not describedfurther herein.

The result of the threshold and current sensor 4236 signal comparison isprimarily of interest during the initial deployment (e.g., during thefirst 0.06 inches of distal movement) of the cutting instrument 4034.Accordingly, the current detection module 4240 may limit the comparisonbased on the distal position of the cutting instrument 4034 as indicatedby the position sensor 4238. The position sensor 4238 may be any type ofposition sensing device suitable for generating a signal indicative of adistal position of the cutting instrument 4034. In one embodiment and asshown in FIG. 91, for example, the position sensor 4238 may be anormally-open Hall effect position switch 4238 that is actuated based onits proximity to a magnet mounted on the ring 4126. The position switch4238 may mounted within the handle 4012 and operate such that when thedistal position of the cutting instrument 4034 (as indicated by theposition of ring 4126) is within a pre-determined distance (e.g., distalposition <0.06 inches) of its proximal-most position, the positionswitch 4238 is closed. Conversely, when the distal position of thecutting instrument 4034 exceeds the predetermined distance (e.g., distalposition >0.06 inches), the position switch 4238 is opened. The positionswitch 4238 may be connected in series with the output of the comparatorcircuit 4248 to limit the comparison based on the position of thecutting instrument 4034. In this way, if the threshold signal isexceeded when the distal position of the cutting instrument 4034 isgreater than pre-determined distance, the output of the position switch4238 will remain at OVDC (according to the example presented above),regardless of the result of the comparison. It will be appreciated thatother types of position sensors 4238 (e.g., mechanically-actuated limitswitches, rotary potentiometers, etc.) may be used instead as analternative to the Hall effect position switch 4238 described above.Additionally, it will be appreciated that auxiliary contacts (not shown)of switch 4158 may be used as an alternative to a separate positionsensor 4238. In embodiments in which the position sensor 4238 does notinclude a switched output (e.g., when the position sensor 4238 is apotentiometer or other analog-based position sensor), additionalprocessing of the position sensor 4236 output using, for example, asecond comparator circuit, may be necessary.

As shown in FIG. 91, the output of the position switch 4238 may beconnected to coil 4244 of relay 4232. Driver circuitry (not shown)between the position switch 4238 and the coil 4244 may be provided ifnecessary. Accordingly, if the signal generated by the current sensor4236 exceeds the threshold signal (indicating activation of the blockingmechanism 4196, 4202, 4216 due to the absence of an unspent staplecartridge 4038), and the cutting instrument 4034 is within thepredetermined distance of its proximal-most position, coil 4244 will beenergized. This causes normally-closed switch of relay 4232 to open,thereby interrupting current flow to the motor 4106 and removing theresistive force exerted by the blocking mechanism 4196, 4202, 4216 uponthe cutting instrument 4034. Importantly, because the blocking mechanism4196, 4202, 4216 need only apply a mechanical blocking force sufficientto cause the threshold signal to be exceeded, the physical stressesexerted by the blocking mechanism 4196, 4202, 4216 are reduced inmagnitude and duration compared to those that would be exerted if onlyconventional mechanical interlocks were used. Furthermore, because theinterlock does not require electronic sensors in the end effector 4016,instrument design is simplified.

FIG. 92 is a schematic diagram of an electrical circuit 4249 of theinstrument 4010 according to another other embodiment of the presentinvention in which a processor-based microcontroller 4250 is used toimplement functionality of the lockout circuit 4241 described above.Although not shown for purposes of clarity, the microcontroller 4250 mayinclude components well known in the microcontroller art such as, forexample, a processor, a random access memory (RAM) unit, an erasableprogrammable read-only memory (EPROM) unit, an interrupt controllerunit, timer units, analog-to-digital conversion (ADC) anddigital-to-analog conversion (DAC) units, and a number of generalinput/output (I/O) ports for receiving and transmitting digital andanalog signals. The current sensor 4236 and the position sensor 4238 maybe connected to analog and digital inputs, respectively, of themicrocontroller 4250, and the coil 4244 of relay 4232 may be connectedto a digital output of the microcontroller 4250. It will be appreciatedthat in embodiments in which the output of the position sensor 4238 isan analog signal, the position sensor 4238 may be connected to an analoginput instead. Additionally, although the circuit 4249 of FIG. 92includes relays 4230, 4232, 4234, it will be appreciated that in otherembodiments the relay switching functionality may be replicated usingsolid state switching devices, software, and combinations thereof. Incertain embodiments, for example, instructions stored and executed inthe microcontroller 4250 may be used to control solid state switchedoutputs of the microcontroller 4250. In such embodiments, switches 4156,4158 may be connected to digital inputs of the microcontroller 4250.

FIG. 93 is a flow diagram of a process implemented by themicrocontroller 4250 according to various embodiments. At step 4252, themicrocontroller 4250 receives the signal generated by the current sensor4236 via an analog input and converts the received signal into acorresponding digital current sensor signal.

At step 4254, values of the digital current sensor signal are comparedto a digital threshold value stored within the microcontroller 4250. Thedigital threshold value may be, for example, a digitized representationof the threshold signal discussed above in connection with FIG. 91. Ifall values of the digital current sensor signal are less than thedigital threshold value, the process terminates at step 4256. If a valueof the digital current sensor signal exceeds the digital thresholdvalue, the process proceeds to step 4258.

At step 4258, the position sensor 4238 input is processed to determineif the cutting instrument 4034 is within the predetermined distance ofits proximal-most position. If the cutting instrument 4034 is not withinthe predetermined distance, the process is terminates at step 4260. Ifthe cutting instrument 4034 is within the predetermined distance, theprocess proceeds to step 4262.

At step 4262, the digital output to corresponding to coil 4244 isenergized, thus causing the normally closed contacts of relay 4232 toopen, which in turn interrupts the current flow to the motor 4106.

In the illustrated embodiment of FIGS. 95-98, the firing trigger 20 mayhave a lower portion 5228 and an upper portion 5230. The upper portion5230 does not have a gear portion that mates with part of the gear drivetrain. Instead, the instrument includes a second motor 5265 with athreaded rod 5266 threaded therein. The threaded rod 5266 reciprocateslongitudinally in and out of the motor 5265 as the motor 5265 rotates,depending on the direction of rotation. The instrument 10 also includesan encoder 5268 that is responsive to the rotations of the main driveshaft 48 for translating the incremental angular motion of the maindrive shaft 48 (or other component of the main drive assembly) into acorresponding series of digital signals, for example. In the illustratedembodiment, the pinion gear 5124 includes a proximate drive shaft 5270that connects to the encoder 5268.

The instrument 10 also includes a control circuit (not shown), which maybe implemented using a microcontroller or some other type of integratedcircuit, that receives the digital signals from the encoder 5268. Basedon the signals from the encoder 5268, the control circuit may calculatethe stage of deployment of the knife 32 in the end effector 12. That is,the control circuit can calculate if the knife 32 is fully deployed,fully retracted, or at an intermittent stage. Based on the calculationof the stage of deployment of the end effector 12, the control circuitmay send a signal to the second motor 5265 to control its rotation tothereby control the reciprocating movement of the threaded rod 5266.

In operation, as shown in FIG. 95, when the closure trigger 18 is notlocked into the clamped position, the firing trigger 20 is rotated awayfrom the pistol grip portion 26 of the handle 6 such that the front face5242 of the upper portion 5230 of the firing trigger 20 is not incontact with the proximate end of the threaded rod 5266. When theoperator retracts the closure trigger 18 and locks it in the clampedposition, the firing trigger 20 rotates slightly towards the closuretrigger 20 so that the operator can grasp the firing trigger 20, asshown in FIG. 96. In this position, the front face 5242 of the upperportion 5230 contacts the proximate end of the threaded rod 5266.

As the user then retracts the firing trigger 20, after an initialrotational amount (e.g., 5 degrees of rotation) the run motor sensor5110 may be activated such that, as explained above, the sensor 5110sends a signal to the motor 65 to cause it to rotate at a forward speedproportional to the amount of retraction force applied by the operatorto the firing trigger 20. Forward rotation of the motor 65 causes themain drive shaft 48 to rotate via the gear drive train, which causes theknife 32 and sled 33 to travel down the channel 22 and sever tissueclamped in the end effector 12. The control circuit receives the outputsignals from the encoder 5268 regarding the incremental rotations of themain drive shaft assembly and sends a signal to the second motor 5265 tocause the second motor 5265 to rotate, which causes the threaded rod5266 to retract into the motor 5265. This allows the upper portion 5230of the firing trigger 20 to rotate CCW, which allows the lower portion5228 of the firing trigger to also rotate CCW. In that way, because thereciprocating movement of the threaded rod 5266 is related to therotations of the main drive shaft assembly, the operator of theinstrument 10, by way of his/her grip on the firing trigger 20,experiences tactile feedback as to the position of the end effector 12.The retraction force applied by the operator, however, does not directlyaffect the drive of the main drive shaft assembly because the firingtrigger 20 is not geared into the gear drive train in this embodiment.

By virtue of tracking the incremental rotations of the main drive shaftassembly via the output signals from the encoder 5268, the controlcircuit can calculate when the knife 32 is fully deployed (i.e., fullyextended). At this point, the control circuit may send a signal to themotor 65 to reverse direction to cause retraction of the knife 32. Thereverse direction of the motor 65 causes the rotation of the main driveshaft assembly to reverse direction, which is also detected by theencoder 5268. Based on the reverse rotation detected by the encoder5268, the control circuit sends a signal to the second motor 5265 tocause it to reverse rotational direction such that the threaded rod 5266starts to extend longitudinally from the motor 5265. This motion forcesthe upper portion 5230 of the firing trigger 20 to rotate CW, whichcauses the lower portion 5228 to rotate CW. In that way, the operatormay experience a CW force from the firing trigger 20, which providesfeedback to the operator as to the retraction position of the knife 32in the end effector 12. The control circuit can determine when the knife32 is fully retracted. At this point, the control circuit may send asignal to the motor 65 to stop rotation.

Although embodiments described above compare the magnitude of thecurrent sensor signal (or a digitized version thereof) to a thresholdsignal or value, it will be appreciated that other metrics for analyzingthe current sensor signal may additionally or alternatively be used todifferentiate between deployment of the cutting instrument 4034 when anunspent cartridge 4038 is installed in the channel 4026 versusdeployment of the cutting instrument 4034 when an unspent cartridge 4038is absent from the channel 4026. For example, the current detectionmodule 4240 or the microcontroller 4250 may be configured to determinederivative and/or integral characteristics of the current sensor signalfor comparison to corresponding thresholds signals or values.Additionally, in certain embodiments the current sensor signal may beprocessed prior to its analysis using, for example, signal conditionersand/or filters implementing one or more filter response functions (e.g.,infinite impulse response functions).

The various embodiments of the present invention have been describedabove in connection with cutting-type surgical instruments. It should benoted, however, that in other embodiments, the inventive surgicalinstrument disclosed herein need not be a cutting-type surgicalinstrument, but rather could be used in any type of surgical instrumentincluding remote sensor transponders. For example, it could be anon-cutting endoscopic instrument, a grasper, a stapler, a clip applier,an access device, a drug/gene therapy delivery device, an energy deviceusing ultrasound, RF, laser, etc. In addition, the present invention maybe in laparoscopic instruments, for example. The present invention alsohas application in conventional endoscopic and open surgicalinstrumentation as well as robotic-assisted surgery.

The devices disclosed herein can be designed to be disposed of after asingle use, or they can be designed to be used multiple times. In eithercase, however, the device can be reconditioned for reuse after at leastone use. Reconditioning can include any combination of the steps ofdisassembly of the device, followed by cleaning or replacement ofparticular pieces, and subsequent reassembly. In particular, the devicecan be disassembled, and any number of the particular pieces or parts ofthe device can be selectively replaced or removed in any combination.Upon cleaning and/or replacement of particular parts, the device can bereassembled for subsequent use either at a reconditioning facility, orby a surgical team immediately prior to a surgical procedure. Thoseskilled in the art will appreciate that reconditioning of a device canutilize a variety of techniques for disassembly, cleaning/replacement,and reassembly. Use of such techniques, and the resulting reconditioneddevice, are all within the scope of the present application.

Although the present invention has been described herein in connectionwith certain disclosed embodiments, many modifications and variations tothose embodiments may be implemented. For example, different types ofend effectors may be employed. Also, where materials are disclosed forcertain components, other materials may be used. The foregoingdescription and following claims are intended to cover all suchmodification and variations.

Any patent, publication, or other disclosure material, in whole or inpart, that is said to be incorporated by reference herein isincorporated herein only to the extent that the incorporated materialsdoes not conflict with existing definitions, statements, or otherdisclosure material set forth in this disclosure. As such, and to theextent necessary, the disclosure as explicitly set forth hereinsupersedes any conflicting material incorporated herein by reference.Any material, or portion thereof, that is said to be incorporated byreference herein, but which conflicts with existing definitions,statements, or other disclosure material set forth herein will only beincorporated to the extent that no conflict arises between thatincorporated material and the existing disclosure material.

What is claimed is:
 1. A cordless surgical instrument for cutting andstapling tissue, comprising: a handle; a battery in the handle; and afiring system, comprising: a shaft extending from the handle; a motor inthe handle, the motor comprising an output connected to the shaft,wherein the battery powers the motor; an end effector connected to theshaft, wherein the end effector comprises a proximal end, a distal end,and a working portion, wherein the proximal end is closer to the handlethan the distal end, and wherein upon actuation of the firing system theworking portion traverses the end effector from the proximal end towardthe distal end; a control circuit in the handle for controlling currentthrough the motor from the battery; and a digital rotary encoder in thehandle that outputs digital signals to the control circuit related torotation of the shaft, wherein the control circuit comprises a relayconnected to the motor, wherein the control circuit is configured to:determine a position of the working portion in the end effector based onthe digital signals from the digital rotary encoder; compare a level ofthe motor current to a threshold motor current level; and change thecurrent supplied to the motor by changing a state of the relay when boththe working portion is within a specified position range in the endeffector and the motor current level exceeds a threshold motor currentlevel for the specified position range.
 2. The surgical instrument ofclaim 1, wherein the control circuit is configured to reduce to zero thecurrent supplied to the motor when the position of the working portionis within the specified position range of the end effector and the motorcurrent exceeds the threshold current level.
 3. The surgical instrumentof claim 2, wherein the specified position range of the end effector isa specified position range at the proximal end of the end effector. 4.The surgical instrument of claim 1, wherein the control circuitcomprises a pulse width modulation controller configured to control thespeed in which the output shaft of the motor rotates.
 5. The surgicalinstrument of claim 4, wherein the handle comprises a user-control that,when activated by a user of the surgical instrument, actuates the firingsystem.
 6. The surgical instrument of claim 1, further comprising astaple cartridge.
 7. A cordless surgical instrument for cutting andstapling tissue, wherein the surgical instrument comprises: a handle; abattery in the handle; and a firing system, comprising: a shaft attachedto the handle; a motor comprising an output connected to the shaft,wherein the battery powers the motor; an end effector connected to theshaft, wherein the end effector comprises a proximal end, a distal end,and a working portion, wherein the proximal end is closer to the handlethan the distal end, and wherein upon actuation of the firing system theworking portion traverses the end effector from the proximal end towardthe distal end; a digital rotary encoder in the handle, wherein thedigital rotary encoder is configured to output signals indicative ofrotation of the shaft; and motor control means, in the handle andconnected to the motor, the battery and the end effector, wherein themotor control means comprises a relay connected to the motor, andwherein the motor control means is for: modulating a width of powerpulses supplied to the motor from the battery; determining a position ofthe working portion in the end effector based on the digital signalsfrom the digital rotary encoder; comparing a level of the motor currentto a threshold motor current level; and changing the current supplied tothe motor by changing a state of the relay when the motor current levelexceeds the threshold motor current level for a specified position rangeof the working portion in the end effector.
 8. The surgical instrumentof claim 7, wherein the motor control means is for reducing to zero thecurrent supplied to the motor when the position of the working portionis within the specified position range of the end effector and thecurrent exceeds the threshold current level.
 9. The surgical instrumentof claim 8, wherein the specified position range of the end effector isthe specified position range at a proximal end of the end effector. 10.The surgical instrument of claim 7, wherein the handle houses the motor.11. The surgical instrument of claim 10, wherein the handle comprises auser-control that, when activated by a user of the surgical instrument,actuates the firing system.
 12. The surgical instrument of claim 7,further comprising a staple cartridge.
 13. A cordless surgicalinstrument for cutting and stapling tissue, comprising: a handle; abattery in the handle; a shaft connected to the handle; an end effectorconnected to the shaft, wherein the end effector comprises a proximalend and a distal end, and wherein the proximal end is closer to theshaft than the distal end, and a firing system, comprising: a cuttingmember configured to move toward the distal end during a firing stroke;a motor comprising an output connected to the shaft, wherein the batterypowers the motor; a rotary encoder in the handle for outputting outputsignals indicative of rotation of the shaft; a pulse width modulationcontroller in the handle to control the speed at which the output shaftof the motor rotates; a control circuit in the handle, wherein thecontrol circuit comprises a relay connected to the motor, wherein thecontrol circuit, and wherein the control circuit is configured to:determine a position of the working portion in the end effector based onthe output signals from the rotary encoder; and compare a currentthrough the motor with a threshold and change the current to the motorby changing a state of the relay when both the working portion is withina specified position range in the end effector and the motor currentlevel exceeds a threshold motor current level for the specified positionrange.
 14. The surgical instrument of claim 13, further comprising astaple cartridge.